Even though a new Ab4d.SharpEngine, a cross-platform rendering engine, was released a few months ago, work on the Ab3d.PowerToys and Ab3d.DXEngine has not stopped. The proof of that is the just published version that brings many great new features and improvements. Here is a list of the most important:

• Added many new options to render pixels and point-clouds.
• Added hardware support to render millions of textures as billboards.
• Added support for Screen Space Ambient Occlusion (SSAO).
• Significantly improved performance of line selection and generating edge lines.
• Added sample that shows how to render objects with glow.

The previous version of Ab3d.DXEngine already provided great support for rendering pixels and point-clouds. It was possible to render millions of pixels with various sizes and colors. There was an OptimizedPointMesh class that could optimize the rendering of large point-clouds. On top of that, the new version adds the following new options:

• The pixel size can be defined in screen or world size. Before, pixel size was defined only in screen size, but now you can also define the size in 3D world size so when using perspective camera the pixels that are farther away from the camera are smaller.
• Pixels can be rendered as rectangles or as circles. Before, only rectangular pixels were possible. Now circular pixels can be rendered and this looks nicer for some point-clouds.
• It is possible to specify a texture that will be rendered on each pixel. This can be used to render millions of billboards that are always facing the camera.
• It is possible to fix the up vector of each pixel so the pixels do not fully face the camera. For example, this can be useful when rendering trees that are always growing vertically and should not face the camera when the camera is looking straight down.
• The Ab3d.DXEngine samples project comes with new PlyPointCloudReader and PlyPointCloudWriter classes (available with full source code). They can be used to read and write point-clouds from and to ply files.

Here are a few screenshots:

(Point-cloud with 12 million points)

(New point-cloud importer sample supports exporting a cropped point-cloud)

(Rendering may 3D textures as billboards. The screenshot shows 15.000 tree textures, but modern GPU can also easily handle much more textures).

Another big new feature is support for Screen Space Ambient Occlusion (SSAO). If you look around you, you can see all the places around the room. All receive at least some light even if the lights or windows do not directly illuminate them. This light is called an ambient light. To correctly render that light, we need to use ray tracing. But in real-time computer graphics, we can usually specify an ambient light with just one value. This will illuminate all the objects in the scene with the same amount of light. But if you look around you, you will notice that, especially at the corners, the amount of ambient light is much lower, and a shadow is visible. Those shadows can be approximated by using the Screen Space Ambient Occlusion. This reduces the amount of the applied ambient light in places that have some objects around them.

See the difference in the following two screenshots (one with and one without SSAO):

Note that to see SSAO shadows, you need to use a lot of ambient light and should not use camera's lights (set camera.ShowCameraLight to ShowCameraLightType.Never). If you are using camera's light, it can illuminate the areas dimmed by the SSAO effect. So, using fixed directional or point lights and strong ambient light is recommended to see SSAO shadows.

The next major change in the new version is not a new feature but a significant improvement of the existing functionality that many of you are using. The new version of Ab3d.PowerToys greatly improves the performance of line selection and generating edge lines.

Showing edge lines can significantly improve the clarity of the shown 3D model. But with the previous version, if you had complex 3D models, calculating edge lines was very slow. The new version significantly speeds up this process. For example, the next graph shows the time in ms that was needed to generate edge lines for a complex P51 oil rig model (3.7 mio triangles; 1000 individual models, some have more than 100,000 positions; CPU: AMD Ryzen 9 5900X):

The previous version required 13 seconds in .Net Framework 4.8 (11 seconds in .Net 8). In the new version, this is almost 50 times faster: 350 ms in .Net Framework 4.8 (280 ms in .Net 8).

So, when using the previous version the user needed to wait for quite a while until the edge lines were generated, but now this is hardly noticeable.

What is more, if you know that your mesh is nicely defined or does not have duplicate positions, you can speed up this process even further. Duplicate positions are very common because they are required to create sharp edges by defining different normals for each position (for example, BoxVisual3D defined 24 positions and not only 6). But if you know that you have a smooth mesh without duplicate positions, you can set the ProcessDuplicatePositions property to false to skip the step of finding and collapsing duplicate positions. Also, if you know that the mesh has nicely defined triangles where each triangle edge is fully covered by any adjacent triangle edge (except on the outer mesh borders), then you can set the ProcessPartiallyCoveredEdges property to false. This skips code to process complex meshes (for example, such complex meshes can be produced by Boolean operations). If users of your application can import any 3D model, then you should have all the settings enabled, but if you have fixed 3D models, then you can experiment by turning off some settings and get even better performance. What is more, the updated "Edge lines creation" sample in Ab3d.PowerToys samples has code that shows how to easily write and read the calculated edge lines to and from a file.

Another very commonly used feature was line selection. The line selection in Ab3d.PowerToys allows selecting lines when the mouse is close to the line (the user can specify the max selection distance). When you were showing a lot of lines or lines have lots of line segments, then the line selection could eat a lot of CPU cycles. Before, 2D screen coordinates were calculated for all line segments. Then the 2D distance from the mouse to each line segment was calculated. The line with the closest distance was the result of the line selection. The new version significantly improves the performance of line selection for lines that have more than 30 segments. In this case, only 2D screen bounding box of the line is calculated and if the mouse position is in the bounding box or close to it, then the 2D screen positions for all line segments are calculated. This can skip a lot of calculations because only lines that are close to the mouse are fully processed. Note that to use the new faster code path, you need to set the new CheckBoundingBox property to true. This is needed to preserve the behavior of the GetClosestDistance method. Before, this method always returned a valid distance value, but now, when CheckBoundingBox is true and when the mouse position is not close to the bounding box, then double.MaxValue is returned.

What is more, if you are using ScreenSpaceLineNodes instead of lines derived from Visual3D objects (this significantly improves the initialization time but is harder to work with), then you can use the new DXLineSelectorData that is the same as LineSelectorData but works with Vector3 structs instead of Point3D structs. This will give you even better performance because of reduced memory usage (using float values instead of double values).

The following screenshot shows a new sample that shows 5000 lines each with 5000 line segments and still achieving super-fast line selection time:

The next new feature did not need any change in the Ab3d.DXEngine library but it just needed a special rendering setup. It is implemented in a new "Glowing objects" sample that can be found in the Advanced section of the Ab3d.DXEngine sample project. As its name suggests, it shows how to render glowing effect to objects with an emissive material. I know that this is not an essential feature, but I am sure that some of you will be able to use it to achieve some very nice visual effects.

As always, there were many other new features, fixes and improvements. You can check them by starting the updated sample projects (Ab3d.PowerToys or Ab3d.DXEngine) and checking for samples with NEW or UP icons. You can get the list of all changed in Ab3d.PowerToys change log and Ab3d.DXEngine change log. 

When speaking about fixes, I would like to mention one nasty bug that occurred when many 3D lines were rendered (using multi-threader rendering), and after the size of the window was changed, then in some cases the lines could be rendered with invalid line thickness. If this also happens in your application, then please upgrade to the latest version. If this is not possible, then disable multi-threader rendering for 3D line or the whole scene (contact support for more info).

Lastly, I would like to mention that the new version comes with a new native Assimp importer that can import 3D models from many 3D file formats. The previous official version of Assimp importer v5.3.1 was released more than half a year ago (2023-09-25). The new version was released just a few days ago (2024-04-07) and comes with many improvements (https://github.com/assimp/assimp/releases). You can build the new version by yourself or get prebuilt dlls from the libs folder in the Ab3d.PowerToys or Ab3d.DXEngine samples.

Here, I would also like to announce that in the coming weeks, I will be releasing a fully managed glTF importer and exporter. This will allow you to import 3D models with full details without using a native Assimp library. Currently, if you do not want to use Assimp importer, you could use ReaderObj (part of Ab3d.PowerToys library) to read obj files or use Ab3d.Reader3ds library to read 3ds files. However, both obj and 3ds file formats have their limitations. Obj files do not support hierarchy and animations, are text only, and have limited materials. 3ds files support only 8.3 file names for textures. So, those two file formats could be used only in a limited number of cases.

On the other hand, the glTF 2 file format is a modern file format that was developed by Khronos group and can store meshes, hierarchies, materials, transformations and animations in a text or binary format. Suppose you distribute 3D models with your application and are currently using Assimp importer to load the models from various files. In that case, you will be able to convert the files into glTF (using Assimp importer and exporter or by using some other third-party or online glTF converter) and then distribute your models as glTF files. This way, you will not need to distribute native Assimp's dlls with your application anymore.

As seen here, the new version can significantly improve the performance of your application and the new features can make it even more visually appealing.

Now, the primary development focus will switch back to the new Ab4d.SharpEngine. I am really happy with the adaptation of the new engine. It seems that the first version already had enough features for many of your projects. Some new features have already been developed, but many are still to be implemented. I am planning to publish a new version in June 2024. So, if you have any feedback or a new feature request for the new version, now is the best time to provide that.

I am happy to inform you that new major versions of Ab3d.PowerToys and Ab3d.DXEngine have been published.

The new release brings many great new features and one bigger breaking change.

The breaking change is the removal of the ViewCubeCameraController:

A customer recently informed me that the ViewCube is patented by Autodesk. It seems that the patent is active only in the USA. See here: https://patents.google.com/patent/US7782319

Therefore I have decided to remove that control from the library. Instead of ViewCubeCameraController the new version of the Ab3d.PowerToys library now provides the CameraNavigationCircles control. See the screenshot of the new sample that demonstrates the CameraNavigationCircles:

And an animation showing that control in action:

As you can see, the new control provides many customization options and can be used in many different ways. What is more, it can replace both ViewCubeCameraController and also CameraAxisPanel.

However, if you are already using the ViewCubeCameraController and would like to continue using it, then please first carefully study the patent, and consult with a layer. If you still want to use the ViewCubeCameraController, then please contact me and I will send you the source code for that control so you will be able to integrate it into your project.

Another major new feature of this release is improved support for line caps (line endings). Previous versions supported only arrow line caps. The new version adds support for additional arrow types, boxes, diamonds and circles. See the screenshot from the new sample that demonstrates that:

What is more, the Ab3d.DXEngine finally gets full hardware acceleration of all 3D lines, including lines with line caps. Before, lines with line caps were generated on the CPU (on each camera change the MeshGeometry3D of the line was regenerated and this was very slow). The new version solves that and moves the generation of the lines to the geometry shader. This means rendering millions of 3D lines with different line caps is now possible.

The new Ab3d.DXEngine also improves line initialization time, so if you define many 3D lines, the engine will show them faster. Also, the order in which lines and other 3D objects are rendered is defined by an improved sorting mechanism, so there should be fewer DirectX state changes when rendering, resulting in slightly faster rendering.

The new release also comes with a new build of native Assimp library that can be used to import 3D models from almost any 3D file format. Unfortunately, it seems that the version number of that library has been stuck at v5.2.5 for almost a year, regardless of hundreds of commits. To still be able to see what version is used, a new GitCommitHash property was added. It returns the Git commit hash of the version. For example, the Assimp library that comes with this release has GitCommitHash set to 0dcfe2f - from 2023-07-03. 

The new Ab3d.PowerToys.Assimp library now also supports reading lights and camera data from the imported file.

There are also many other improvements and fixes. Even though a lot of time was spent on the new Ab4d.SharpEngine, the list of changes is still very long - see the change logs for Ab3d.PowerToys and Ab3d.DXEngine.

I am really glad to inform you that the first beta version of the Ab4d.SharpEngine has been published. 

Ab4d.SharpEngine is a cross-platform 3D rendering engine for desktop and mobile .Net applications.

The existing rendering engine, Ab3d.DXEngine, uses DirectX 11. Because of that, it can only be used on Windows. The new engine uses Vulkan API.  And because it is built using .NET 6, the new engine is truly cross-platform and can be used on Windows, Linux (including Raspberry PI 4), macOS, Android and iOS. 

I know that now you would want to ask me: what about web? I am monitoring the status of Blazor with WebAssembly. I think that things are developing in the right direction but currently this technology is not yet capable enough for a more complex application with 3D graphics. The main problem is that WebAssembly does not have direct access to the Canvas, so each call needs to go through java script. Because 3D rendering engine needs to execute a lot of WebGL (or WebGPU) calls, this would be very slow. Also, in my opinion web will always be slow for high end and demanding 3D graphics. Anyway, the long time plan is to also provide support for web so that the same c# code could also run in a browser.

Vulkan is also an API with very little overhead, which makes it much faster than DirectX 11. What is more, Vulkan supports all new features that are added to new graphics cards, including ray tracing. This does not mean that Ab3d.DXEngine already supports ray tracing, but it is possible to add that and other new features in the future.

Because the new rendering engine was built from the ground up, it was possible to use all the know-how and experience from Ab3d.PowerToys and Ab3d.DXEngine to make its programming API clean and very easier to use. I admit that when using Ab3d.DXEngine and Ab3d.PowerToys, the API is not very nice in all cases. The Ab3d.PowerToy was built on top of WPF 3D objects that are not very extendable, so some compromises were needed (for example, cameras are derived from FrameworkElement and not from Camera). Also, Ab3d.DXEngine converts all WPF 3D and Ab3d.PowerToys objects into its own objects. This means that the application has two versions of each object. In other cases, some tricks must be used to provide Ab3d.DXEngine features to Ab3d.PowerToys and WPF 3D objects (for example using SetDXAttribute). Therefore, having an easy-to-use API was one of the primary goals of the new engine. Please contact me if you have any recommendations or find something that bothers you. 

I hope that you are already excited about the new rendering engine.
In that case, just jump into the samples page on GitHub: Ab4d.SharpEngine.Samples

There you will find solutions that show how to use the Ab4d.SharpEngine with WPF, AvaloniaUI, WinUI 3, SDL, Glfw. Some samples will run only on Windows; some will also run on Linux and macOS. Some will run on Android. iOS samples are coming in the near future. I also plan to add support for WinForms and MAUI. If you know of any other well know UI framework, please let me know and I will try to provide support for that too.

Check also the readme on GitHub as it provides a lot of other information.

Because you are an existing user of Ab3d.PowerToys and Ab3d.DXEngine, you are probably very interested in comparing the new engine with the current libraries.

Let's start with advantages of Ab3d.DXEngine and Ab3d.PowerToys:

• Ab3d.DXEngine and Ab3d.PowerToys are very mature products that are tested and proven in the "field" by many customers.
• Those two libraries currently provide more features and come with more samples that can be used as code templates for your needs.
• Ab3d.DXEngine supports multi-threading and currently provides faster 3D rendering in many use cases.
• Ab3d.DXEngine can use software rendering when there is no graphics card present (for example in virtual machines or on a server).
• Ab3d.DXEngine and Ab3d.PowerToys can run on older .Net versions, including .Net Framework 4.5+.

Advantages of Ab4d.SharpEngine:

• Ab4d.SharpEngine can run on multiple platforms. You can start writing code for Windows and later simply add support for Linux, macOS, Android and iOS. Or port just a smaller part of the application to other platforms.
• Ab4d.SharpEngine uses Vulkan API that is the most advanced graphics API. It is actively developed and gets new features as new versions of graphics cards are released. This provides options to support all current and future graphics features (for example Ray tracing - not possible with DirectX 11).
• As mentioned before, Ab4d.SharpEngine has a very clean and easy to use programming API. 
• Working with WPF objects is very slow (accessing DependencyProperties has a lot of overhead). Also, Ab3d.DXEngine needs to convert all WPF objects into its own objects. Working with objects in Ab4d.SharpEngine is much faster.
• Vulkan is a significantly faster graphics API than DirectX 11. Though the Ab4d.SharpEngine does not use all the fastest algorithms yet (no multi-threading), in the future the engine will be significantly faster than Ab3d.DXEngine.
• Ab4d.SharpEngine is built on top of .NET 6 and that provides many performance benefits because of using System.Numerics, Span and other improved .NET features.
• In the future Ab4d.SharpEngine will provide more functionality than Ab3d.DXEngine with Ab3d.PowerToys.

So, if you have a big and complex application that uses Ab3d.PowerToys and Ab3d.DXEngine, I would not recommend you to try to port it to the new engine. You could not just copy and paste the code to the new engine. Though the ideas and principles of both engines are still the same, for example there are TargetPositionCamera and MouseCameraController - both with almost the same properties and methods. But there are many smaller differences, for example BoxVisual3D is now BoxModelNode. Anyway, if you know how to use the existing engine, you will feel very familiar with the new engine also.

But if you are starting to build a new application with 3D graphics or would like to port some smaller part of your big application (for example a viewer with a few additional functionalities) to a more mobile format, then the new engine is a perfect choice for that. Also, if you are curious about how to program in .NET for other platforms or will have a little bit more time in December, I would be really glad if you could try the new engine and provide some feedback (you can also use Discussions or Issues on GitHub, or simply use email, forum or feedback form).

But please don't be too demanding. This is the first open beta and some things may not work as expected. In those cases, please see the Troubleshooting section on GitHub for more info.

Let me also share the planned road map for the new engine.

In the following weeks and months I will try to release new beta versions with fixes and improvements. After a few months, probably in Q2 or maybe in Q3 2023, the first production-ready versions should be released. Maybe some parts of the engine will remain in beta, for example AvaloniaUI, MAUI, macOS and iOS support. The plan is to have the main and most common parts ready for production: Windows (WPF, WinForms, SDL, Glfw), major Linux distributions (SDL, Glfw) and Android. 

And finally, I would like to assure you that Ab3d.PowerToys and Ab3d.DXEngine will still be actively developed, will get new releases and features and will have full support in the future!

I hope that the new engine will allow developers to use the beautiful c# language to create amazing apps with 3D graphics that could run on all possible platforms. If you have the right tools, then even 3D graphics is not hard!

And of course: Merry Christmas and happy new year!

New versions of Ab3d.PowerToys and Ab3d.DXEngine have just been released. The new versions bring many great new features and because they were released just after the .Net 7 release, the new versions also come with a new .Net 7 build.

Because this release is also linked to a new .Net version release, this blog post also shows some performance numbers related to running Ab3d.DXEngine by using different .Net versions. See the end of this blog post for more information.

Now back to new features. In the past there were many requests to improve the triangulator that was part of the Ab3d.PowerToys library. If we want to show a filled 2D shape, for example an ellipse, as a 3D object, we need to first convert 2D points to 3D points and then define the triangles that will connect the positions. This can be done by using a triangulator. The old version of Ab3d.PowerToys already has a triangulator, but it could process only simple polygons. This was improved in the new version so that the new triangulator can now process multiple polygons and also supports polygons with holes.

As seen from the image above, this allows generating a 3D mesh from any text (text is represented by a series of 2D shapes). The sample also shows how to generate a 3D mesh from multiple 2D shapes (ellipses, rectangles, paths with bezier curves, etc.). The lower part of the sample shows individual triangles that were generated. There is also a Slider control that can be used to show how the triangles are laid out from the first to the last.

In some cases the new triangulator can also be used instead of Boolean operations. This requires that the main 3D object has a constant height (for example represents a sheet of metal or wood). In case when user wants to subtract a cylinder or some other object that can be extruded from a 2D shape, then using the triangulator instead of a Boolean subtract operation will be much faster and will provide better results (fewer triangles will be created).

Another highly requested feature is better support for collision detection. By using bounding boxes it was already possible to do some collision detection. However, because the bounding box is only an approximation of the space occupied by the object, this was not very precise. The new version of Ab3d.DXEngine brings a new MeshCollider object that can be used to check if one 3D position is inside another 3D mesh. By checking all the positions of one mesh, it is possible to check if one mesh collides with another mesh. The new sample demonstrates that (when checking the sample use arrows, PgUp and PgDown keys):

An interesting new material type that will greatly simplify work for some users is the new FaceColorMaterial. It supports defining different colors for each of the triangles in the mesh. Before it was already possible to achieve that by using a VertexColorMaterial. But this required that the positions of the mesh were duplicated so that each triangle used its own unique set of positions. Now this is greatly simplified because the original mesh can be used. What is more, by setting the alpha color to zero, the individual triangles can be discarded from rendering. The new sample nicely demonstrates that:

Improving the performance of the Ab3d.DXEngine is a never-ending job. This version brings two new performance improvements. The first one is for those that use DXEngine's SceneNode objects and meshes. The new version significantly improves performance of hit testing because it can use OctTree objects on DXEngine's meshes. Before OctTree objects were created only from WPF's MeshGeometry3D objects. 

OctTree object organizes the triangles in a mesh in hierarchically organized 3D space regions so that when triangles are checked if they are intersected by a 3D ray, the number of checked triangles is much much lower. This makes hit testing almost instant even on huge meshes.

Now the DXScene.DXHitTestOptions.MeshPositionsCountForOctTreeGeneration property is also used when doing hit tests on DXEngine's meshes. Its default value is 512. This means that an OctTree will be automatically generated when the mesh has more than 512 positions. You can also manually generate the OctTree by calling the CreateOctTree method.

The second performance improvement will be great news for those who are rendering many polylines (lines where line segments are connected to each other). Multiple polylines are usually defined by a single MultiPolyLineVisual3D object. But though one object is used to define multiple lines, each line was still rendered by its own DirectX draw call. And if there were thousands of lines to render, it took quite some time to issue draw calls for each line. The good news is that with the new version, all the polylines can be rendered with only one draw call. This means that there will be almost no CPU cost for rendering any number of polylines.

As always, there are also many other improvements and fixes. See the change logs for more details here: Ab3d.PowerToys changelog and Ab3d.DXEngine changelog. Also get the latest samples (Ab3d.PowerToys.Wpf.Samples and Ab3d.DXEngine.Wpf.Samples) and check for UP and NEW icons to see new or updated samples.

And as promised before, let me show you some additional performance numbers. Each .Net version brings many performance improvements. There are new classes that can be used to write faster code. But also existing .Net code can run faster because each version improves the JIT compiler so it produces faster assembler code. The following graph shows how performance of the Ab3d.DXEngine can be improved when the application is run in a newer .Net version (running in .Net 4.8 is shown with a blue rectangle that represents 100% of the time; running in .Net 6.0 and .Net 7.0 executed the code faster and therefore the rectangles are shorter):

(1) "Multi-threading and caching" sample was run with showing 20000 boxes, using no background threads and disabled DirectX caching. The DrawRenderTime performance parameter measures the time that Ab3d.DXEngine needs to issue all DirectX draw calls. This requires going through all objects, checking their state, setting the DirectX state and calling DirectX Draw method. In this sample most of the time is spent in native DirectX code so the performance gains cannot be huge. But still, there is almost 10% better rendering performance just by using a newer .Net version.

(2) "Instanced animated arrows" sample was run with showing 1 million arrows. The graph shows values for the time that is required to calculate 1 million transformation matrices - each matrix is defined so that an arrow mesh will point toward the animated sphere. The values are based on highly optimized code (manually inlined and optimized math operations) that run on multiple threads (using Parallel.For).

(3) "Instanced animated arrows" sample showing 1 million arrows but this time the source code without any manual optimization is executed. The graph shows that the new JIT compiler can greatly optimize the generated assembler and in this case can provide a 25% performance boost.

(4) "Transparency sorting performance" sample shows the performance of different sorting algorithms that sort 3D objects to prevent transparency artifacts (the sample was updated to show 7200 instead of 720 boxes). The values under (4) show the difference of sorting that sort WPF 3D objects and is implemented by TransparencySorter from Ab3d.PowerToy library. Working with WPF objects is not very fast and there will be no changes in the WPF to make this faster. So it is great news that only using a new version of .Net can significantly improve the performance.

(5) The values here are again from the "Transparency sorting performance" sample, but this time showing the performance improvements of the transparency sorting from Ab3d.DXEngine. The source code for this sorting algorithm is already highly optimized, but still newer versions of .Net can squeeze some more juice from that.

So, Microsoft, keep up the great work!

And finally, the first open beta version of the new Vulkan based cross-platform rendering engine will be available before the end of this year! Let's conclude with the new logo for the engine:

I am happy to inform you that new versions of Ab3d.PowerToys and Ab3d.DXEngine libraries have been published.

This is a maintenance release with many improvements, fixes, and some new features.

The most interesting new feature in the Ab3d.DXEngine is added support for XRayEffect. The XRayEffect can render objects that look as they would be photographed by an x-ray. This can be useful when you work on a complex model with many parts and want to select one part while the other parts are just barely visible. In that case it is possible to make other parts semi-transparent. Another option that is available with the new version is to use the new XRayEffect or XRayMaterial. This works especially well when showing models with many triangles and with curved shapes. See example (this is a screenshot from slightly modified XRayEffect sample):

The new XRayEffect can be also used in the updated "Model Viewer" sample in the Ab3d.DXEngine samples (to use it check the new "Use X-Ray material" CheckBox in the second tab).

Another new feature can be used by those who use object instancing to render thousands of objects and want to do fast hit testing on the instanced objects. In this case, the new version allows rendering instance id bitmap from instanced objects. This generates a bitmap where colors represent the ids of the instances. By checking the color at a specific pixel, you can get the instance id that was rendered at that screen coordinates. This can also be used to do a rectangular selection or selection of the instance around the mouse cursor.

Also, the standard RenderToBitmap method got an improvement. With the new version it is possible to get direct access to the memory of the rendered bitmap. This way you can reuse the WritableBitmap or use any other method of using the rendered image. This is very useful when you are calling RenderToBitmap method very often because you can optimize and reuse the used objects (before a new WritableBitmap object was created on each call of RenderToBitmap method and this could generate many objects on the large memory heap).

The new version also improves stability in case of disconnecting an external monitor. Stability is also improved in some cases when rendering through a remote desktop.

The previous version introduced two-sided material that doubles the performance of rendering models that had the same front and back side materials. But this did not work in all the cases. This version fixes this issue.

There are also some other fixes and improvements. See the full list here: https://www.ab4d.com/DXEngine-history.aspx

The Ab3d.PowerToys library also got a few new features and improvements.

One interesting new feature is an improved algorithm for extruding a shape along a path. Now you can use two new options. One is to preserve the size of the shape at junctions and the other is to preserve the orientation of the shape's Y direction. See screenshot (the right side shows the extruded model using the new option):

The new version of the library also comes with an updated Assimp importer and exporter. It now supports reading embedded textures and saving textures into fbx and glft files. There is also a new native Assimp library v5.2.3 that should improve the accuracy of importing and exporting files (https://github.com/assimp/assimp/releases/tag/v5.2.3)

To see the full list of changes see the change log here: https://www.ab4d.com/PowerToys-history.aspx

You can get the new version by updating the NuGet packages or by downloading the new evaluation or commercial version from your User Account web page. Note if you are using libraries from NuGet and you have recently renewed the updated subscription, then you will probably need to generate a new license activation code for the new version to work (this code can be generated from your User Account web page).

The list of new features is not as long as with some previous versions. The reason for this is that a lot of development effort is now spent on the new Vulkan based rendering engine (Ab3d.SharpEngine). This new engine is progressing very well. This engine will be fully cross-platform so the same code should be able to run on many different hardware devices. Recently we were able to run the code that works on Windows and desktop Linux on Raspberry Pi with a small touch screen attached - see photo:

Such a setup makes the engine great for controlling some industry machines or equipment.

The engine can also work on Android:

Many features from Ab3d.PowerToys and Ab3d.DXEngine were already ported to the new engine. But before releasing an alpha version, the core of the engine still needs some polishing and testing. I expect that the first alpha can be released in a month or two. The plan is to release a closed alpha version and later an open beta version. If you are interested in trying the new engine, please write me an email or feedback and you will be informed when the alpha version is available. This will allow you to test the engine on your hardware and on your devices. It will aso give you some influence on which features will make it to the first official and production-ready version.

I am happy to inform you that new major versions for Ab3dPowerToys and Ab3d.DXEngine libraries have been released. 

The Ab3d.DXDXEngine has reached version 5.0. This is the 21st release of the library. The Ab3d.PowerToys library has climbed even higher and has reached version 10.0, having the 34th release of the library. The high number of releases is even more impressive when checking the actual change logs (see https://www.ab4d.com/PowerToys-history.aspx and https://www.ab4d.com/DXEngine-history.aspx). The long list of new features and changes that were often requested by the users shows that the libraries have become very mature and that they can be used for many different types of business, technical and scientific applications with 3D graphics. To make the numbers even more interesting, the build number of the new version is set to 8000. Because the build number is calculated as the number of days since 1st January 2000, this means that this release has happened on the 8000th day of the new Millenium (on 26th November 2021).

The highlights of the new versions are:

• New Model viewer sample.
• Rendering two-sided materials in one render pass.
• Triangles sorting for transparent meshes.
• Updated assimp importer that can read 3D models from almost any file format.
• Added FitIntoView method for FreeCamera.

The first great new added value of the new version is a new Model viewer sample:

This sample does not provide any new feature but demonstrates many features of the Ab3d.PowerToys and Ab3d.DXEngine libraries. And because almost any application with 3D graphics requires object loading, mouse selection, wireframe and solid object rendering and showing object hierarchy, the sample is an excellent source of code snippets that you can use in your applications.

You can also use the sample to inspect the 3D models that are loaded from many file formats with Assimp importer. As shown in the following screenshot, it is possible to show mesh normals, position indexes and triangle orientations for the selected model:

Additional information can be obtained when an object without children (a GeometryModel3D) is selected. Then clicking on the "Show info" button will show the details about the mesh with a generate c# code that defines the mesh (creating arrays for all positions, normals, texture coordinates and triangle indices).

I am sure that you will find the new Model viewer interesting. Now let me provide some information about new features. Let me start with some background knowledge.

In 3D graphics the most fundamental building block of a 3D object is a triangle. And each triangle has its front and its backside. By default the front side of the triangle is the side where the vertices are defined in counter-clockwise order. The backside is the other side where the vertices are defined in clockwise order (see more here https://www.khronos.org/opengl/wiki/Face_Culling). In 3D graphics you can assign one material to the front side of the triangles and another material to the back side of the triangles. When using a GeometryModel3D object, the front material is assigned to the Material property, and the backface material is set to the BackMaterial property.

Many times the 3D models are solid and closed so we cannot see inside the 3D model. In those cases we can render only the front sides of the triangles and skip rendering the backsides. This reduces the number of rendered pixels by half. For example, 3D box and 3D sphere are solid and closed models and therefore the graphics card does not need to render the inner sides of the triangles. But when rendering a 3D plane, opened cylinder or any other model with holes, the graphics card needs to render both front and back triangles (both Material and BackMaterial properties need to be set). This is needed because the user can rotate the camera to see the other side of the plane or inside the model. The other case when we need to render both sides is when the object uses semi-transparent material. There the user can see the inner side of the 3D model. The models that use the same material for both the front and back sides are described as using a two-sided material. Two-sided materials are used many times for all the objects in technical 3D graphics.

Usually, the rendering of two-sided materials is done in two passes. First, the backside of the material is rendered, then the front side is rendered. When rendering the backside, the DirectX rasterizer state needs to be changed to prevent culling (skipping) the backside. Also, the code in the shader needs to invert the normal vector so that the lighting calculations are correct. This means that rendering models with two-sided material requires two DirectX draw calls and therefore takes twice as much time as rendering models with single-sided materials (actually, there is also an additional performance penalty because of rasterizer state changes).

The new version of Ab3d.DXEngine can use the DirectX SV_IsFrontFace semantics (https://docs.microsoft.com/en-us/windows/win32/direct3dhlsl/dx-graphics-hlsl-semantics) that is used in the shader to check if the front side or the backside of the triangle is being rendered. This information is needed to invert the normal in the case of backside rendering. Also, the backside culling needs to be disabled in the DirectX rasterizer state. This allows the new version of Ab3d.DXEngine to render two-sided materials in one rendering pass. This means that 3D scenes where all 3D models have two-sided materials will be rendered twice as fast as before.

When using DXEngine's materials (supported by StandardMaterial, VertexColorMaterial, PhysicallyBasedMaterial and WpfMaterial), the two-sided rendering can be enabled by setting the IsTwoSided property to true. When using WPF 3D objects, then two-sided rendering will be used when the Material and BackMaterial on the GeometryModel3D are set to the same material instance. This will set the IsTwoSided property to true in the DXEngine's WpfMaterial that is created from the WPF's material. 

It is possible to prevent this new functionality by changing the static DXViewportView.UseTwoSidedMaterialsForSolidObjects and DXViewportView.UseTwoSidedMaterialsForTransparentObjects fields. As seen from the field names, there are different settings for solid and for transparent objects. By default, solid two-sided objects are rendered in one rendering pass (UseTwoSidedMaterialsForSolidObjects is true). But by default, transparent objects are still rendered in two passes (UseTwoSidedMaterialsForTransparentObjects is false) - first rendering the back material and then the front material. This is needed to preserve the rendered result as it was before. It is possible to set the UseTwoSidedMaterialsForTransparentObjects to true, but then it is recommended to set the new DefaultTransparentDepthStencilState field to DepthRead (from DepthReadWrite). This will render transparent objects in one render pass and correctly render the inner side of the objects. See the new "TwoSided materials" sample for more info.

The next new feature of the engine is the support for sorting individual triangles in a mesh. This may be required when showing semi-transparent meshes that have complicated geometry, as for example the following torus knot:

On the left the screenshot shows the object without sorted triangles. Red arrows mark the parts that are not correctly visible through the mesh. Green arrows indicate the correctly rendered pars of the object. Note, if the object would be rotated to the other side, then the correctly visible parts would change.

The new version of Ab3d.DXEngine has a highly optimized triangle sorting code that works on low-level triangles and positions data (WPF's MeshGeometry3D objects are not used because they are very slow). The code changes the data in the index buffer. After sorting is done on the CPU, then the changed index buffer needs to be sent to get GPU. Those two processes can take some time, so you should consider using triangle sorting only when really needed. 

Ab3d.DXEngine has got some other great new features and bug fixes. And there are also two new additional samples that are designed to improve understanding of GraphicsProfiles and different options to render wireframe lines. See screenshots:

The Ab3d.PowerToys library also got some great new features. In my opinion the most important new feature is an updated Assimp importer. The Assimp importer is a third-party native library that can import 3D models from more than 40 file formats. The previous version 5.0.1 of Assimp was released a long time ago, in January 2020. After that release, the library got many improvements and also some breaking changes that crashed the .Net wrapper. But because there was no increase in the library's version number, it was not possible to update the wrapper to work with the newer build of the library. Finally, on 20th November (last week) a new official version 5.1.1 of Assimp library was released. This meant that it was possible to update the AssimpNet (.Net wrapper for the native library) and the Ab3d.PowerToys.Assimp library (helper library that converts the read 3D models into WPF 3D objects). The new libraries improve support for many file formats and add some new file formats to the supported list.

Those two libraries and the compiled native Assimp library are available with the new Ab3d.PowerToys sample on GitHub (https://github.com/ab4d/Ab3d.PowerToys.Wpf.Samples/tree/master/lib). Those libraries are also installed by the evaluation installer of the AB4D products (https://www.ab4d.com/Downloads.aspx) and the commercial installer for the Ab3d.PowerToys library (available from User Account web page).

The new version of Ab3d.PowerToy also comes support for calling the FitIntoView method when using FreeCamera (a highly requested feature). This provides the same functionality to FreeCamera as available by the TargetPositionCamera.

As always, please update to the new versions and check the new samples projects (https://github.com/ab4d/Ab3d.DXEngine.Wpf.Samples, https://github.com/ab4d/Ab3d.PowerToys.Wpf.Samples). In the new samples check the samples that are marked with NEW and UP icons. The icons mark new samples and the samples that were updated in the last version (hovering the mouse over the UP icon will show you more information about the change).

In this short blog post I would like to inform you that a new Ab3d.DXEngine.Assimp library has been published. It can be used to import 3D objects from many file formats into Ab3d.DXEngine objects.

The library is available with full source code on GitHub: https://github.com/ab4d/Ab3d.DXEngine.Assimp.

It is also available as a NuGet packge: https://www.nuget.org/packages/Ab3d.DXEngine.Assimp

Before this new library was published, it was also possible to import 3D objects into Ab3d.DXEngine objects, but this required using Ab3d.PowerToys.Assimp library. That library first converted native assimp objects into managed objects in Assimp.Net library, then converted those objects into WPF 3D objects and finally converted that into Ab3d.DXEngine objects. This took much longer and required more memory.

Now with the Ab3d.DXEngine.Assimp library it is possible to convert the native assimp objects directly into the Ab3d.DXEngine objects. The library creates the following objects:

• MeshObjectNode for objects with meshes
• SceneNode objects for groups of objects
• SimpleMesh<PositionNormalTexture> for meshes
• StandardMaterial for materials

The new library is using a Silk.NET.Assimp library as a wrapper library (instead of an old Assimp.Net library that Ab3d.PowerToys.Assimp uses).

Because of Silk.NET.Assimp the new library can currently work only in x64 processes (I have added an issue to the Silk.NET.Assimp GitHub repository about the problem in x86 process so hopefully, this will be solved soon).

Though the Ab3d.DXEngine.Assimp is much faster then Ab3d.PowerToys. Assimp, it also have the following limitations compared to Ab3d.PowerToys.Assimp:

• cannot read animation data (Ab3d.PowerToys.Assimp can read animations and even play skinned animations by using Ab3d.PowerToys)
• cannot read polygon data (polygon indices are read by Ab3d.PowerToys.Assimp into MeshGeometry3D).
• cannot export 3D scene into file by using assimp as an exporter.

Anyway, if you only need to import 3D objects and you are using Ab3d.DXEngine that in it worth checking the new importer. Some missing features will be added in the future versions.

As a sidenote, I would also like to inform you that at the beginning of this week, a new hotfix version of Ab3d.DXEngine was published. It fixes a few issues mainly related to using multiple DXViewportView objects. The change log can be read here: https://www.ab4d.com/DXEngine-history.aspx

If you are using multiple DXViewportView objects, then it is highly recommended to upgrade to that version.