Point Cloud GLSL

Hi TouchDesigners,

I am wondering can I achieve a trail effect with this particular setup, without rewriting the GLSL code? Not a feedback but transforming the particles in some kind of ribbons or splines. Thank you in advance!

I think a few people have done ribbons by wiring that positions TOP into a Cache TOP whose depth is the number of points in the Line1 SOP. Then they modify the GLSL to look at the correct pixel in the 2D Texture Array of the Cache TOP. (There’s a more optimized way of keeping everything in a single large 2D texture rather than a 2D texture array but it’s more complicated.) And then the GLSL code can either be set to wireframe mode, or you can insert a geometry shader to do the ribbons. Wireframe is automatic and sometimes ugly, but ribbons require calculating the derivative of the line at the point being rendered.

Also, depending on the effect you want, a Feedback+Over+(Level with 0.99 opacity) network can give decent trails.

P.S. The “Techniques” board is for finished techniques, so this thread is better suited for General Discussion or Beginners.

Thanks David!