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#Actualpondwater

Posted 06 September 2012 - 05:55 PM

I've been using Assimp to convert models into a nice runtime format. However Assimp does not seem to load/store the bind shape matrix of a given mesh.

This is not to be confused with a bind matrix for skinning. The bind shape matrix is a transformation matrix in which every vertex of a mesh must be transformed by to be in its proper location and orientation in the model.

For example, lets say my COLLADA model is composed of two equal sized cubes, one centred on the origin and one stacked on top of it. In this case, the vertices of both cube meshes will be identical, but one of them will have a translation component in it's bind shape matrix to move it into its proper location.

At first I thought Assimp would simply bake the vertices since thats what I was going to do anyway but it doesn't do that. I checked the *aiNode for the mesh in the scene graph thinking maybe it will store it in its mTransformation field but those only have an identity matrix.

Does anyone know what happens to these matrices and/or where I could find it in the scene graph?

#1pondwater

Posted 06 September 2012 - 05:31 PM

I've been using Assimp to convert models into a nice runtime format. However Assimp does not seem to load/store the bind shape matrix of a given mesh.

This is not to be confused with a bind matrix for skinning. The bind shape matrix is a transformation matrix in which every vertex of a mesh must be transformed by to be in its proper location and orientation in the model.

For example, lets say my COLLADA model is composed of two equal sized cubes, one centred on the origin and one stacked on top of it. In this case, the vertices of both cube meshes will be identical, but one of them will have a translation component in it's bind shape matrix to move it into its proper location.

At first I thought Assimp would simply bake the vertices (aiProcess_PreTransformVertices) since thats what I was going to do anyway but it doesn't do that. I checked the *aiNode for the mesh in the scene graph thinking maybe it will store it in its mTransformation field but those only have an identity matrix.

Does anyone know what happens to these matrices and/or where I could find it in the scene graph?

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