AB4D Forum - Ab3d.DXEngine

Forum closed, use Issues on GitHub instead

Wed, 01 Apr 2026 13:47:35 +0200

This forum is closed because of problems with sending emails.

Please use Issues or Discussions on the GitHub Ab3d.DXEngine.Wpf.Samples repo.

Optimizing Duplicate Model Imports

Fri, 27 Mar 2026 09:18:30 +0100

For the purposes of a simulation built on the DXEngine and PowerToys, a very large number of high-poly models of the same .obj file must be imported on a low-spec system.

I have a Model class which encapsulates WPF's ModelVisual3D and is constructed using the Model3D returned by an instance of AB3D's ReaderObj. An optimization specific to this use-case has already been implemented, whereby we obtain this Model faster by using the CloneCurrentValue extension on Model3Ds generated from a .obj file we've previously imported from. This has the benefit of running our turing machine over the tape in memory rather than that of the disk, but still performs quite poorly on startup. Is there a known/supported method of obtaining many independent Model3Ds from one .obj I am overlooking here?

Ab4d.OpenCascade loading IGES files, entity names are lost

Sat, 18 Oct 2025 13:24:03 +0200

HI,

I am having trouble loading IGES files and preserving the original entity names.

It seems in opencascade it is possible to configure if to preserve entity names, but this is not exposed in the reader. (I assume this is what is happening but I don't have deep knoweldge of IGES).

Right now all my objects are being called COMPOUND, but I know from opening the CAD elsewhere that there is something in the name, but it is getting lost.

Is it possible for CadPart to access more entity names/IDs/paths etc?

I may be able to send you the CAD file in question but cannot post here for confidentially reasons.

Thanks for any help!

Skybox issue

Thu, 18 Sep 2025 14:52:09 +0200

Hi i wonder if anyone can help me get rid of seams in my skybox, and also the top seems to render darker than the rest ! can anyone help me please

[Image: https://www.graphix.org.uk/downloads/sbtest.jpg]

Adding and Removing External Monitors causes DeviceRemoved Crash

Tue, 08 Apr 2025 00:02:29 +0200

I'm currently a little stumped with a crash in my application that's happening because of a DeviceRemoved exception that's being thrown:

Code:

HRESULT = 0x887A0005

HRESULT: [0x887A0005], Module: [SharpDX.DXGI], ApiCode: [DXGI_ERROR_DEVICE_REMOVED/DeviceRemoved], Message: 

-2005270523

HRESULT: [0x887A0005], Module: [SharpDX.DXGI], ApiCode: [DXGI_ERROR_DEVICE_REMOVED/DeviceRemoved], Message: 

Ab3d.DXEngine

 at Ab3d.DirectX.CompleteRenderingStep.b(DXDevice a, Boolean b) at Ab3d.DirectX.CompleteRenderingStep.OnRun(RenderingContext renderingContext) at Ab3d.DirectX.RenderingStepBase.Run(RenderingContext renderingContext) at Ab3d.DirectX.DXScene.ao(RenderingContext a) at Ab3d.DirectX.DXScene.am(RenderingContext a, Boolean b, Boolean c, DXScene d)

Boolean b(Ab3d.DirectX.DXDevice, Boolean) @ Ab3d.DirectX.CompleteRenderingStep

SharpDX.SharpDXException

Device removed in RenderScene The most probable reason for this error is that the graphics driver was updated while the application was running. DeviceRemovedReason: HRESULT: [0x887A0007], Module: [SharpDX.DXGI], ApiCode: [DXGI_ERROR_DEVICE_RESET/DeviceReset], Message: The GPU will not respond to more commands, most likely because some other application submitted invalid commands. The calling application should re-create the device and continue. 

Ab3d.DXEngine

 at Ab3d.DirectX.DXScene.HandleDeviceRemoved(String message, SharpDXException sharpDxException) at Ab3d.DirectX.DXScene.am(RenderingContext a, Boolean b, Boolean c, DXScene d) at Ab3d.DirectX.DXScene.RenderScene(Boolean forceRender, Boolean forceUpdate) at Ab3d.DirectX.Controls.DXView.RenderScene(Boolean forceRender, Boolean forceUpdate) at Ab3d.DirectX.Controls.DXView.j(Object a, EventArgs b) at System.EventHandler.Invoke(Object sender, EventArgs e) at System.Windows.Media.MediaContext.RenderMessageHandlerCore(Object resizedCompositionTarget) at System.Windows.Media.MediaContext.RenderMessageHandler(Object resizedCompositionTarget) at System.Windows.Threading.ExceptionWrapper.InternalRealCall(Delegate callback, Object args, Int32 numArgs) at System.Windows.Threading.ExceptionWrapper.TryCatchWhen(Object source, Delegate callback, Object args, Int32 numArgs, Delegate catchHandler)

Void HandleDeviceRemoved(System.String, SharpDX.SharpDXException) @ Ab3d.DirectX.DXScene

Ab3d.DirectX.DXEngineException

For context, this is specifically happening when a monitor is connected or disconnected from the computer, including when a computer goes to sleep and disconnects/reconnects to its monitors, although it's somewhat sporadic. It most consistently happens when I maximize the application, reduce it again, and then plug or unplug a monitor. My initial instinct is that it's related to the resolution changing/the swap buffer being resized as mentioned in the Microsoft docs but it doesn't explain some of the crash scenarios.

My current setup a WPF Viewport3D wrapped in the DXViewportView, with the DirectXImage presentation type. Our application is a VB.NET/WPF app, target framework is .NET 4.8.

I've done a few other troubleshooting steps if it's helpful at all:

I've reproduced this issue on multiple different Windows computers - I believe they were all Windows 11, but could be wrong.
I've gotten this crash by unplugging and replugging one or more monitors, regardless of if the application is currently displayed on the monitor - but not all the time. Again, it seems to always happen if the application has been maximized/full screen at any point while it's running, and then the monitors change. Otherwise, it happens about 1 in 3 times that I plug/unplug a monitor.
Manually changing the resolution of a monitor doesn't seem to cause the crash.
Changing the presentation type of the viewport to DirectXOverlay seems to solve the issue. I can't tell for certain, but running the software with the presentation type changed, I've been able to do at least 10 cycles of connecting and disconnecting monitors, full screen and not, without any crashes. Unfortunately, we have a few WPF overlays and backgrounds that make switching over to that presentation type a little difficult. If it's the only fix, I could try and make it work, but would prefer to stick with DirectXImage for now. I'm also not 100% confident that it does fix the issue since... I'm not sure what's causing it to begin with.
I can reproduce this in the target .NET 4.8 version of the DXEngine samples app. I haven't been able to reproduce it in the .NET 8.0 version, but going back to the olden days of 4.8 and unplugging/replugging the monitors crashes it with a similar error to my own application.

I know this is a bit of a shot in the dark, but I'm hoping there's some guidance for what I might be doing wrong or missing in my application, or if this is a bug somewhere further than my application (and hopefully a fix for it too!). It might just be a 'need to update WPF and .NET framework' as well. Happy to provide more code/context for how it's setup - I'm pretty new to DXEngine!

As an aside, I'm working on adding in a handler for the DXEngine DeviceRemoved event so that we can handle it gracefully and save/reload all the visual data, but would still like to find the root cause of the issue/bug since it seems like it's probably not intended behavior and the DXGI error shouldn't be raised here (I think?).

DXViewportView.RenderToBitmap no longer working

Fri, 28 Feb 2025 14:09:37 +0100

Hello, Just updating AB4D to the latest version from v7.1 and it looks like it has broken some of my code for doing an offscreen render then saving to a bitmap.

Calling RendToBitmap on a DXViewportView used to work. But now it's just a blank image. Rendering the camera still works, but is very slow.

Any ideas on a fix?

Best regards,

Simon

Code snippet below

Code:
  var viewport3D = new Viewport3D();

            var directxViewPort = new DXViewportView();

            directxViewPort.InitializeScene();

            directxViewPort.BeginInit();

            directxViewPort.Viewport3D = viewport3D;

            directxViewPort.Height = 2048;

            directxViewPort.Width = 2048;

            viewport3D.Width = 2048;

            viewport3D.Height = 2048;

            var camera = new FirstPersonCamera();

            camera.Position = new Point3D(0, 0, 0);

            camera.Bank = 0;

            camera.Heading = 0;

            camera.Attitude = -90;

            camera.FieldOfView = 92;

            camera.TargetViewport3D = viewport3D;

            foreach (var m in objs.Values)

            {

                viewport3D.Children.Add(m.CreateModelVisual3D());

            }

            camera.Refresh();

            directxViewPort.EndInit();

            var img2 = directxViewPort.RenderToBitmap(2048, 2048, -1, 96, 96);  //this line used to work, but now the image is just blank

            var img = camera.RenderToBitmap(backgroundBrush);  //this works but is very very slow

Anchor arrow as EndLineCap of an LineArcVisual3D doesn't work

Fri, 11 Oct 2024 14:00:00 +0200

When I try to put an Arrow Anchor as EndLineCap for a LineArcVisual3D, doesn't show the arrow.
In this example doesn't work any other type of arrow anchor.
Ab3d.Visuals.LineArcVisual3D supportArc = new LineArcVisual3D();
supportArc.CircleCenterPosition = new Point3D(0,0,0);
supportArc.CircleNormal = new System.Windows.Media.Media3D.Vector3D(0, 1, 1);
supportArc.Radius = 2.5;
supportArc.ZeroAngleDirection = new System.Windows.Media.Media3D.Vector3D(1, 0, 0);
supportArc.StartAngle = 300;
supportArc.EndAngle = 30;
supportArc.EndLineCap = Ab3d.Common.Models.LineCap.ArrowAnchor;
supportArc.LineThickness = 2;
supportArc.LineColor = supportsColor;

Ab3d.DXEngine.Wpf.Samples.net80 compilation errors with AssimpPbrHelper

Tue, 30 Apr 2024 16:21:37 +0200

I pulled the latest DXEngine sample project from Github yesterday with the intent of looking at the new functionality in 7.0. I also pulled the PowerToys sample project for 11.1.

I'm registered for both DXEngine and PowerToys and have 7.0.8865 and 11.1.8864, both updated from Nuget, VS2022 (all patches applied) and I'm using the .net80 versions of each project.

The PowerToys project compiled and ran without issues.

The DXEngine project does not compile as-is. The problems are in AssimPbrHelper.cs in functions SetupPbrMaterials() and UpdatePbrMap()

There are four errors, each stemming from assimpWpfImporter, and all for misisng fields/properties/functions.
assimpWpfImporter.LastImportedFileName
assimpWpfImporter.AssimgWpfConverter
assimpWpfImporter.LastUsedTexturesPath
assimpWpfImporter.GetEmbeddedTexture()

I was able to compile the DXEngine sample but commenting out the majority of the two above mentioned functions. The Pbr samples don't run, but I expected that. Everything else seems fine.

Any suggestions? It's not critical, I don't need those particular samples, I just prefer to minimize the number of changes I have to github samples, so I need to reapply changes if I pull a new version (I'm already adding in my licensing info to both apps so I can keep a running version available to look at, at need - as well as let some of our engineers see what capabilities your libraries make easy).

I examined the Ab3D.DXEngine.Wpf.Samples\lib folder (as references in the .csproj) and the date on Ab3D.PowerToys.Assimp.dll is 2024/04/29, as is Assimp32.dll and Assimp64.dll. Assimpnet.dll is 2023/10/28

GPU Instancing Support in Ab4d.SharpEngine or Ab3d.DXEngine

Fri, 06 Oct 2023 14:10:42 +0200

Hello AB4D Team,

I am interested in the capabilities of Ab4d.SharpEngine and Ab3d.DXEngine concerning GPU Instancing. Does either of these libraries currently support GPU Instancing, or is there a plan to support this feature in upcoming releases?

Thank you for your time.
Best regards.

Lines created via WpfModelVisual3DNode no longer render in version 6.0

Sun, 09 Jul 2023 11:56:59 +0200

In a scenario using DxEngine directly in a WinForms app, lines (Ab3d.Visuals.LineVisual3D, Ab3d.Visuals.PolyLineVisual3D) created via WpfModelVisual3DNode no longer display when using version 6.0 of DxEngine

Please find a sample solution with one project using 5.0 and one using 6.0 illustrating the issue:

https://drive.google.com/drive/folders/1...drive_link

DXEventManager3DWrapper performance

Wed, 29 Mar 2023 12:23:59 +0200

We're using DXEventManager3DWrapper to perform hittesting, but we're seeing some performance issues in certain cases.

Specifically we're seeing issues when a key is pressed. Any other who has the same issues?

Andrej: I have emailed you regarding this issue, but haven't yet heard anything. Did you receive my e-mail?

IMultiMapMaterial read only

Thu, 26 Jan 2023 17:35:40 +0100

the interface imultimapmaterial is read only so how do i add my material list ??

Code:
#Region "Assembly Ab3d.DXEngine, Version=5.1.8153.1045, Culture=neutral, PublicKeyToken=d45c8e156fba2841"

' F:\Users\kevan\Documents\VS2022 Projects\x3DViewer\DLL\Ab3d.DXEngine.dll

#End Region

Imports System.Collections.Generic

Imports SharpDX.Direct3D11

Namespace Ab3d.DirectX.Materials

    '

    ' Summary:

    '     IMultiMapMaterial interface defines TextureMaps property that is a list of Ab3d.DirectX.Materials.TextureMapInfo

    '     objects and is used to define a material that uses multiple texture maps.

    Public Interface IMultiMapMaterial

        '

        ' Summary:

        '     Gets a list of Ab3d.DirectX.Materials.TextureMapInfo object that defines texture

        '     maps that should be rendered with this material.

        ReadOnly Property TextureMaps As List(Of TextureMapInfo)

        '

        ' Summary:

        '     Gets a BlendState that is used to render the base texture. If null a Ab3d.DirectX.CommonStates.Opaque

        '     or a Ab3d.DirectX.CommonStates.PremultipliedAdditiveBlend (in case of transparency)

        '     will be used.

        ReadOnly Property BlendState As BlendState

    End Interface

End Namespace

i have this declared
Public Property MY_PBRmaterial As IMultiMapMaterial

when i try to add a texture to the list my app crashes

MY_PBRmaterial.TextureMaps.Add(_textureMapInfo) 'BREAKS HERE

so how do i add my textures to the list ?

Getting center rotation (pivot) from FBX asset imported

Fri, 04 Nov 2022 05:33:01 +0100

I already loaded a 3d delta robot using assimp importer, the 3d model was defined in 3DS with rotations pivots (local view) and exported to FBX, so, when i load using assimp importer I am getting the model3d parts with a definition that includes the name of the 3dmodel + Assimp__Rotation, giving the opportunity to add rotation transformation and perfor the rotation from the defined pivod in 3ds. What I am not able to find, it is how to get the center rotation wold coordinates of this pivot.

Any suggestions?

thanks in advance
JC

Model Rotator and ViewCubeCameraController Behavior

Sat, 25 Jun 2022 01:25:29 +0200

Hi, I am having problems using two of your UI tools for rotating my models and was hoping you could explain where I am going wrong in my thinking.

I have a 3D scatter plot and need to be able to rotate the entire model in any orientation.

When I use the ViewCubeCameraController, it works great except when the cube is inverted (Y is pointing down). When this happens, rotating the cube with the mouse using the cube faces is the inverse of what I would expect (the disk rotations work fine). In fact, trying to use the mouse to rotate in the XY plane is generally backwards of what I would expect. I assume this is because I am moving the camera and not the model (which is conceptually what I actually need to do).

I also played with using the ModelRotatorVisual3D that moves with the model (e.g., the Rotator with StandardTransform sample) and it is almost perfect for manipulating my plot except... It stops working when rotated in 2 different axes. In other words, if I spin the rotator in X it works great but if I then try and rotate on other axes it gets confused and the actions on the rotator no longer seem to track what it "should" do.

Thanks again for any help you can provide!

RenderSpritesRenderingStep disposal

Thu, 23 Jun 2022 11:11:13 +0200

Hi,

I've been tracking some resources and found, that RenderSpritesRenderingStep might not be correctly disposed (or displayed). When I log the tracked resources, all rendering steps except sprite, are marked as disposed. In the collection there are some wpf objects (grid and lines), lights, no sprites.

I've added the log (lines 14, 37) where there is an entry for the rendering step. I've tried version 5.0.8000 and 5.1.8153.

Best regards,
Janovsky Roman

Tracked Resources:

1 Ab3d.DirectX.DXDevice DISPOSED 'DXDevice'
2 Ab3d.DirectX.EffectsManager DISPOSED
3 Ab3d.DirectX.CommonStates DISPOSED
4 Ab3d.DirectX.TextureCache DISPOSED
5 Ab3d.DirectX.ContextStatesManager DISPOSED 'MainThread-ContextStatesManager'
7 Ab3d.DirectX.Controls.DXViewportView
8 Ab3d.DirectX.DXDevice 'DXDevice'
9 Ab3d.DirectX.DXScene DISPOSED
10 Ab3d.DirectX.InitializeRenderingStep DISPOSED 'Initialize': InitializeRenderingStep Name: 'Initialize'
11 Ab3d.DirectX.PrepareRenderTargetsRenderingStep DISPOSED 'PrepareRenderTargets': PrepareRenderTargetsRenderingStep Name: 'PrepareRenderTargets'
12 Ab3d.DirectX.RenderObjectsRenderingStep DISPOSED 'StandardRenderObjects': RenderObjectsRenderingStep Name: 'StandardRenderObjects'
13 Ab3d.DirectX.ResolveBackBufferRenderingStep DISPOSED 'StandardResolveBackBuffer': ResolveBackBufferRenderingStep Name: 'StandardResolveBackBuffer'
14 Ab3d.DirectX.RenderSpritesRenderingStep 'RenderSprites': RenderSpritesRenderingStep Name: 'RenderSprites'
15 Ab3d.DirectX.CompleteRenderingStep DISPOSED 'Complete': CompleteRenderingStep Name: 'Complete'
16 Ab3d.DirectX.RenderingStepsGroup DISPOSED 'RenderPostProcessingGroup': RenderingStepsGroup Name: 'RenderPostProcessingGroup' (DISABLED)\r\n - PreparePostProcessingRenderingStep Name: 'PreparePostProcessing' (PARENT DISABLED)\r\n - RenderPostProcessingRenderingStep Name: 'RenderPostProcessing' (PARENT DISABLED)
17 Ab3d.DirectX.RenderPostProcessingRenderingStep DISPOSED 'RenderPostProcessing': RenderPostProcessingRenderingStep Name: 'RenderPostProcessing'
18 Ab3d.DirectX.PreparePostProcessingRenderingStep DISPOSED 'PreparePostProcessing': PreparePostProcessingRenderingStep Name: 'PreparePostProcessing'
19 Ab3d.DirectX.EffectsManager
20 Ab3d.DirectX.CommonStates
21 Ab3d.DirectX.TextureCache
22 Ab3d.DirectX.ContextStatesManager 'MainThread-ContextStatesManager'
23 Ab3d.DirectX.Models.WpfVisual3DCollectionNode DISPOSED RefCount: 0 'Viewport3D.Children': WpfVisual3DCollectionNode (23) 'Viewport3D.Children' (DISPOSED) (NOT INITIALIZED) (IsActuallyVisible: false)
31 Ab3d.DirectX.Controls.DXViewportView DISPOSED 'MainDXViewportView'
32 Ab3d.DirectX.DXScene DISPOSED
33 Ab3d.DirectX.InitializeRenderingStep DISPOSED 'Initialize': InitializeRenderingStep Name: 'Initialize'
34 Ab3d.DirectX.PrepareRenderTargetsRenderingStep DISPOSED 'PrepareRenderTargets': PrepareRenderTargetsRenderingStep Name: 'PrepareRenderTargets'
35 Ab3d.DirectX.RenderObjectsRenderingStep DISPOSED 'StandardRenderObjects': RenderObjectsRenderingStep Name: 'StandardRenderObjects'
36 Ab3d.DirectX.ResolveBackBufferRenderingStep DISPOSED 'StandardResolveBackBuffer': ResolveBackBufferRenderingStep Name: 'StandardResolveBackBuffer'
37 Ab3d.DirectX.RenderSpritesRenderingStep 'RenderSprites': RenderSpritesRenderingStep Name: 'RenderSprites'