rectangular light frustum?

General TouchDesigner Discussion
1

i searched on the boards and couldn’t really find any info on this.

is there any way you know of to make a rectangular frustum for a light comp instead of the conical one?

is it a matter of creating one in the internal sop structure? i couldn’t seem to get that to work.

thanks!

2

No, the internal SOP structure is just a visual model of the lighting code in the Light COMP, so changing the SOP geometry will have no effect on the output of the light.

3

You would need to make a custom GLSL shader to do this.

4

Wouldn’t it be enough to put a white rectangle from a TOP into the projector map parameter of the Light COMP?

5

so-

i managed to make a rectangular light mask using networks. this .toe is a little messy, but the idea is-

using a known FOV, apply the FOV to a projection (projangle) in step one. in step two, project a rectangular mask with the scene’s width and height using the known projangle. in step 3 combine the two images and re-project the composite at full FOV.

the effect i need is to be able to independently mask the light, while modifying projection map’s applied uv. in this .toe there are two sliders. the horizontal slider adjusts the fov, while the xy slider adjusts the uv mapping.

so yes- hrtlacek is right- but, in order to use a TOP as a 2d mask with “wrapping” projector extend modes i needed that extra third step.

i would love to do this with a shader but i’m still too much of a glsl novice!
custom_rectangular_conelight_mask.toe (10.7 KB)