Forums > Jitter

jit.gl.mesh origin

April 13, 2010 | 5:22 am

How do I make the origin of jit.gl.mesh equal to the center of the object? The origin seems to be offset by default. I’ve modifed some of the example patches to use the luma from a movie as a displacement map. I did this by enabling matrix output on a jit.gl.gridshape and then inputing it into jit.gl.mesh. The result is a rutt etra style distortion on a 3d object. I need the sphere that is created to have a center origin, so I can accurately rotate a camera around the object. Please help.

– Pasted Max Patch, click to expand. –

April 13, 2010 | 3:23 pm

a bit of a big patch to digest… but looking at this quickly it seems that the luma part is a bit over complicated, what about jit.rgb2luma?

secondly, i would try to get it to work on a plane as it will be easier to work out what is going on with the 3d… on my setup it looks like the z depth is tilted at 45degrees < ?>

also why jit.op average the luma mesh and the jitgl.gridshape mesh… shouldnt that be multiplied < ?>

hope that helps,

j


April 13, 2010 | 3:54 pm

Justin,

It was the jit.op @op avg that was the issue. I can’t remember why I chose that over * but there it is. Now the sphere rotates around its radius. Thank you!


April 13, 2010 | 4:00 pm

well i’d like to take the kudos, but i didnt have much time to look at ur patch and decided to take a guess… ;p
glad it helped out, and nice patch BTW.

j


April 13, 2010 | 11:24 pm

Here is a cleaned up version of the patch for anyone interested in making a video create a displacement map for a 3D object, in this case using jit.gl.mesh. This patch is extrapolated from jitter-eamples and the jit.gl.mesh help file. I’ve also included an equation for a camera orbiting a sphere based on the scale (radius). If you adjust the camera lookat, you wont just be staring at the origin. jit.lumakey gave me a lot more control than jit.rgb2luma, so I kept it. jit.rota mirrors the video so the displacement map is textured more seamlessly than without. You will need to adjust its params based on the jit.qt.movie’s dimensions. The p scalebiased texture may be unnecessary. Enjoy, because sharing is fun. Read a movie, adjust the lumakey and you should be in business. Mode 1 on lumakey makes subtle distortions. Change it to Mode 0 or 2 and watch the abstract craziness begin. The dim amount makes the model less or more complex.

– Pasted Max Patch, click to expand. –

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