   glMultiMatrixf and D3DXMatrixMultiply
  Hi,...glMultiMatrixf(Matrix.e);DrawUpperArm();// some calculation// Setting Matrix to the lower arm frameglMultiMatrix(Matrix.e);DrawLowerArm();// some calculation// Setting Matrix to the hand frameglMultiMatrix(Matrix.e)DrawHand();I wonder in this case1.D3DXMatrixMultiply(&aFrame->TransformationMatrix, &aFrame->TransformationMatrix, &mata);// this is fine // same calcalution as above, setting matb to the elbow frame// Should I do this?D3DXMatrixMultiply(&aFrame2->TransformationMatrix, &aFrame2->TransformationMatrix, &matb);//====================================================================// or2.D3DXMatrixMultiply(&aFrame->TransformationMatrix, &aFrame->TransformationMatrix, &mata);// this is fine// add upperarm frame to the transformation// calculate elbow frame as matbD3DXMatrixMultiply(&aFrame2->TransformationMatrix, &aFrame2->TransformationMatrix, &aFrame->TransformationMatrix);D3DXMatrixMultiply(&aFrame2->TransformationMatrix,&aFrame2->TransformationMatrix, &matb);//====================================================================3.or I need to update the combined transformation as well//======================================================================Ill-formed elbow matrix was formed currently.. don't know what to do next!I have some code to update the combined transformation later on,So I doubt it to do that individually.Thanks for any helpJack[Edited by - lucky6969b on June 16, 2009 4:20:34 AM]