   Vertex to World
  Hello,I have been trying to get a triangle position from the vertex buffer and get its position in the world, but without success.I took a vertex took its XYZ, added with the mesh position in the world, but its not really giving me the right positions.The vertex have D3DFVF_XYZ.The coords im taking from the vertex are rights, same for the mesh position in the world.I thought i need to use maybe the camera matrix, i really don't know :SAny idea how to get the real position ?Thanks alot.   
  The vertex buffer contains the position of the vertex untrasformed generally (except for pretrasformed vertex)If you need to know the world position of the vertex you need to multiply that vertex by the world matrix. (only adding the translation part of the matrix may not account other kind of trasformation like scaling or rotation)   ;  thats where im stucked at, when i rotate the location is not right.How the hell i can multiply a VECTOR3(in the vertex i have a vector3 which are the coords) with a Matrix Oo ?thanks for helps :)   ;  Try to use Vector4's in place of Vector3's, as they're often required even though you think you're not using the fourth component.XNA Vector4.Transform:    [m11 m12 m13 m14] [X Y Z W] * [m21 m22 m23 m24]   [m31 m32 m33 m34]   [m41 m42 m43 m44] ;Quote:Original post by yoni1993thats where im stucked at, when i rotate the location is not right.How the hell i can multiply a VECTOR3(in the vertex i have a vector3 which are the coords) with a Matrix Oo ?thanks for helps :)in hlsl it is "mul(vector, matrix)"in cpu c++ code it is "D3DXVec3TransformCoord(vectorresult, vectorsource,  matrix)"   