[solved] Castle Particle Emitter rise Emitter Exception: 'No mesh found in this model'

Recongalina · April 28, 2025, 12:49pm

Hello!
After a recent or little earlier update, I found that Castle Particle Emitter started rise an exception ‘No mesh found in this model’:

github.com/Kagamma/cge-3d-particle-emitter

src/CastleParticleEmitter.pas

f0a0c6ef8


      
          begin
            if not URIFileExists(Self.FEffect.MeshAsSourcePosition) then exit;
            glGetIntegerv(GL_MAX_TEXTURE_SIZE, @MaxTextureSize);
            Scene := TCastleScene.Create(nil);
            Scene.URL := Self.FEffect.MeshAsSourcePosition;
            try
              try
                // We only care the first shape
                ShapeList := Scene.Shapes.TraverseList(True);
                if ShapeList.Count = 0 then
                  raise Exception.Create('No mesh found in this model');
                Shape := ShapeList.Items[0];
                ShapeNode := Shape.Node as TShapeNode;
                //
                IndexedTriangleSetNode := ShapeNode.FindNode(TIndexedTriangleSetNode, False) as TIndexedTriangleSetNode;
                CoordNode := ShapeNode.FindNode(TCoordinateNode, False) as TCoordinateNode;
                VertexList := CoordNode.FdPoint.Items;
                //
                ActualTextureSize := Min(MaxTextureSize, VertexList.Count);
                SetLength(TextureData, ActualTextureSize);
                for I := 0 to VertexList.Count - 1 do

For my project I made a temporary fix:

github.com/SerufuYua/project_nya

code/particle/CastleParticleEmitter.pas

60292b8cb


      
          begin
            if not URIFileExists(Self.FEffect.MeshAsSourcePosition) then exit;
            glGetIntegerv(GL_MAX_TEXTURE_SIZE, @MaxTextureSize);
            Scene := TCastleScene.Create(nil);
            Scene.URL := Self.FEffect.MeshAsSourcePosition;
            try
              try
                // We only care the first shape
                ShapeList := Scene.Shapes.TraverseList(True);
                if ShapeList.Count = 0 then
                  Exit;
                Shape := ShapeList.Items[0];
                ShapeNode := Shape.Node as TShapeNode;
                //
                IndexedTriangleSetNode := ShapeNode.FindNode(TIndexedTriangleSetNode, False) as TIndexedTriangleSetNode;
                CoordNode := ShapeNode.FindNode(TCoordinateNode, False) as TCoordinateNode;
                VertexList := CoordNode.FdPoint.Items;
                //
                ActualTextureSize := Min(MaxTextureSize, VertexList.Count);
                SetLength(TextureData, ActualTextureSize);
                for I := 0 to VertexList.Count - 1 do

Еhis exception also rises in the demo project gallery

I compile projects using Lazarus and Castle Editor under Windows. In both cases the Exception appears.

kagamma · April 28, 2025, 2:26pm

I just update CGE to latest commit and I don’t have this issue after compiling the gallery demo. I suspect your version of CGE has a buggy implementation of URIFileExists() so maybe try to update your CGE to latest commit and see if the issue still exists.

Recongalina · April 29, 2025, 7:40am

I updated CGE from Latest release and Castle Particle Emitter but nothing changed for me.
Maybe it’s because I’m compiling to 32-bit… I’ll check 64-bit too.

CGE:

Lazarus:

Recongalina · April 29, 2025, 8:14am

No, in 64-bit I have same issue… Ah I think I understand! You told “update CGE to latest commit”. I’m using release ver of CGE. So looks like it mean, that I need just to wait next release. Ok.

kagamma · April 29, 2025, 11:59am

Thanks I can reproduce the issue now.
I made a small change to the source code to avoid the issue, please redownload CastleParticleEmitter.pas and try it again.

Recongalina · April 29, 2025, 12:45pm

Thank You! It working

michalis · April 29, 2025, 11:24pm

From what I can see, this is something I should ultimately fix in CGE too.

History: Some time ago, around the beginning of March, when making zip class, I changed how UriExists and UriFileExists are implemented. I did changes to enable custom URL protocols to register custom callback to tell “does given URL exist”.

Looks like, along the way, I also changed the UriExists('') and UriFileExists('') answers. By mistake, UriExists('') became ueUnknown (because it has no recognized protocol…) and UriFileExists('') became true (because it may exist as a file since it’s ueUnknown).

Fixed now, in Fix UriExists and UriFileExists for '' · castle-engine/castle-engine@00a253a · GitHub . UriExists('') is now ueNotExists and UriFileExists('') is false.