Flexible projection mapping

Mar 18, 2011 at 7:53pm

Flexible projection mapping

Hi guys I was hopping someone can point me in the right direction on how to achieve this for a project of mine


I’m trying yo use jit.gl.nurbs with a keystone patch I found in the forums, but honestly I don’t understand why you need a 5 plane matrix for each corner.

I don’t know if a better approach could be using jit.lcd to define mesh vertex…

how do i get control points to define the shapes I want to map?

– Pasted Max Patch, click to expand. –

Hope someone can help!

Thank you very much

Mar 27, 2011 at 5:29am

Hello !!!
Someone that care to explain ??

Thank you!

Mar 28, 2011 at 5:21am

You should be able to extrapolate those 4 control points into more. if you look you have a couple sets of data you have the sort of x, y and z position first, but I forget what the other two numbers are. I thought I remembered them being something related to texture, but changing them doesn’t seem to actually do anything…but you do need them there

I extrapolated your patch into something more useful..something I’ve been meaning to do for a while myself..but compare the two to see what i changed (notably the first matrix size from a 2 2 to a 4 4, yielding the 3×3 grid) and then just rote manual positioning. This would look different on a videoplane with a proper aspect ratio though. the points wouldnt be off screen

– Pasted Max Patch, click to expand. –
Mar 28, 2011 at 7:41pm

you only need a 3 plane matrix for a gl.nurbs projection mapping solution. the 3 planes correspond to x,y,z positions of the control vertices. you also don’t necessarily need to upsample the 3×3 matrix to 20×20 as the nurbs handles interpolation internally, but i suppose that’s a personal preference.

for a gl.mesh solution, you do need a 5 plane matrix. the last two planes are texture s and t values. the gl.nurbs object handles texturing internally, whereas the gl.mesh object needs explicit texture parameters (the last two planes).

Feb 28, 2013 at 4:17am

Hi, I'm getting a distortion from the 4×4 grid, can anyone care to provide a solution.

thanks in advance,



  1. ScreenShot20130227at8.02.49PM.png
Feb 28, 2013 at 6:14pm

got it sorted.

the number of the grid will have to match, 4 4. (see image)


  1. ScreenShot20130228at10.08.16AM.png
Feb 28, 2013 at 6:33pm

Would love to give this a try. Would you be so kind as to post the example?

Mar 1, 2013 at 2:08am

Got it, very nice.


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