   rotation's pivot
  I think i miss somethings about geometry pipeline. I can't understand why the rotation pivot of my object is a side. See this image for understand the question: I load model in x format and then from gui i change mAngle of object, then://============================================//World MatrixD3DXMATRIX matRot;D3DXMATRIX matRoty;D3DXMATRIX matTras;D3DXMATRIX matscaling;D3DXMatrixIdentity(&mWorldMat);D3DXMatrixRotationY(&matRoty,(D3DX_PI*3/2 - mAngle)+D3DX_PI);D3DXMatrixTranslation(&matTras,mPosW.x,mPosW.y,mPosW.z);D3DXMatrixScaling(&matscaling, mModelScaling,mModelScaling,mModelScaling);mWorldMat=matscaling*matRoty*matTras;After this i use a standard PhongLight shader.The question is: The model is modelled around 0 origin in 3ds , why the pivot of rotation is a side of this 3d Arc ?Hope someone can help me.Thx for your time.   
  forgot about the line:D3DXMatrixRotationY(&matRoty,(D3DX_PI*3/2 - mAngle)+D3DX_PI);Just consider this like:D3DXMatrixRotationY(&matRoty,mAngle);The others arguments is for consider 90 degree north.Thx again.   ;  Rotation matrices will rotate your object around the world origin. You want to translate the object to the centre, rotate, and translate back again.   ;Quote:Original post by TheUnbelieverRotation matrices will rotate your object around the world origin. You want to translate the object to the centre, rotate, and translate back again.Yes but even if I usemWorldMat=matRoty;In this case there is no translation, only rotation and the rotation is about center of world, i got the same result.. Indeed in this example the translation matrix is an Identity, and following you is like translate to origin ,rotate and translate back again. Right ?   ;  ok nvm, that side is exacly the world origin. I can't understand why but this is.. I think a problem in the exporter or something like that.I just load the model and put on the world with all matrix identity and the origin is just that side.Edit: I made a cube 10x10x10 where the center is exacly in the 0 origin of 3ds max, and everthings are ok.Thx TheUnbeliever.[Edited by - repka3 on April 10, 2010 6:48:31 PM]