   Does a scaling matrix affect rotations?
  Let's say I have two world matrices:world1 = worldRotation * worldTranslation * Matrix.CreateScale(0.5f);world2 = worldRotation * worldTranslation;The first world matrix has it's drawing size and translation scaled but not the rotation.Is this normal?  Do scaling matrices affect rotation at all?   
  Yes this is normal:)What is the behavior you're trying to achieve? Are you trying to create a matrix that has "half" the effect of the stuff before the scale?   ;  Thanks for the reply!I'm not really trying to achieve anything.  I'm just trying to understand matrices and 3D programming.So are you saying that scale matrices only affect drawing and translation?   ;Quote:Original post by sofakngSo are you saying that scale matrices only affect drawing and translation?Scale matrices affect only size. A scale matrix multiplies the distance each vertex is from the origin by a given number. So a vertex at (2,4) would now appear to be at (1,2). This is the case regardless of how the vertex got there -- by having that as its object-space coordinates, or by moving there from a translation.   ;  Ok, I think I understand.  Thanks!Instead of starting a new topic, let me ask one more question but this time about backface culling.If we are using a backface culling mode of counter-clockwise (eg. counter-clockwise vertices are not drawn), than why does this rectangle still work:// Triangle-strip:verts = new VertexPositionColor[4];verts[0] = new VertexPositionColor(new Vector3(-1, 1, 0), Color.Blue);verts[1] = new VertexPositionColor(new Vector3(1, 1, 0), Color.Yellow);verts[2] = new VertexPositionColor(new Vector3(-1, -1, 0), Color.Green);verts[3] = new VertexPositionColor(new Vector3(1, -1, 0), Color.Red);The first three vertices are clockwise so that makes sense, but the last three (eg. 2nd triangle strip) are actually counter-clockwise...EDIT: Apparently DirectX (XNA) flips the culling flag for every even numbered triangle.Sorry for the wasteful post.[Edited by - sofakng on May 12, 2009 8:28:58 AM]