Linear control matrix grid in nurbs


    Aug 01 2010 | 7:35 pm
    I hope my english is comprehensible...
    I need to keystone a video on a curved surface. The classic 4 corner pin keystoning isn't suitable for my needs, since I also need to correct the distortion of the plane on the projection surface.
    I thought that a nurb with a video-texture would have been a solution so I downloaded the Jitter Recipes Book n°2 and messed with the Recipe 18: Manipulator, to learn the basics.
    The patch is almost perfect, but the control point grid generated by the message exprfill "snorm[0]" is not a linear grid. You could see it by activating the "draw as mesh" toggle. It's a grid that is somewhat larger on the sides and narrower at centre. In fact, the attached video texture has a slight barrel distortion.
    I tried to change the message, but I couldn't figure out what is the right function to generate a simple equidistant grid of control points. Can someone help me?
    My patch is very similar to Recipe 18, but, here it is anyway:

    • Aug 01 2010 | 9:52 pm
      Hello, When you send order 1 1 it looks equidistant, doesn't it ? cheers Hubert
    • Aug 01 2010 | 9:52 pm
      I'm sorry, adding the message ctlshow $1 made me realize that the control matrix is perfectly linear. The problem is in the mesh itself and how the video texture is applied to it. Some advice?
    • Aug 01 2010 | 9:53 pm
      Yes, when I send order 1 1 it looks equidistant... I have a lot to learn, thanks...