Is it possible to visualize ray length info as a black and white map?

Question

Prompted by my previous question, Is it possible to see the output of a node group like this one: (created from this tutorial on blender cookie)

Nod group output

as a easy to visualize (and quick to render) black and white map like this?:

enter link description here

Simply connecting the output of the group to an emission shader does not let rays through the object, so the output is white:

enter image description here

kivig · Accepted Answer · 2013-10-30T17:55:57.877

6

Connecting the emission shader directly, as you suggested won't work indeed, but how about mix of transparent and emission depending on Geometry->Backfacing? Should work.

Edit: Works for me: enter image description here

edited Oct 30 '13 at 17:55

answered Oct 29 '13 at 20:38

kivig

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Just tested, doesn't seem to work. – gandalf3 Oct 29 '13 at 20:39
Edited the answer. Like this? – kivig Oct 29 '13 at 20:58
It still seems transparent though.. – gandalf3 Oct 29 '13 at 21:01
It's not. It does illuminate scene, though. But that can be solved by adding another mix with diffuse for non-camera rays – kivig Oct 29 '13 at 21:03
I must be doing something wrong.. With this node setup I got this. – gandalf3 Oct 29 '13 at 21:57
You connected HSV node to backfacing flag instead of ray length. It was intended to map ray length to match desired lightness, not control transparency. – kivig Oct 29 '13 at 22:49
Thanks, it works, but only with other geometry to bounce rays into it. Could you update the screenshot in your answer to the correct node setup? – gandalf3 Oct 29 '13 at 23:48
Actually it works without extra geometry, I seem to have found a bug. – gandalf3 Oct 30 '13 at 02:40
"I found a bug... Aaand it's gone" :) Updated setup. Sorry - didn't notice before :) – kivig Oct 30 '13 at 17:58

score 1 · Answer 2 · answered Oct 29 '13 at 20:10

One way is to connect it to a Transparent shader:

enter image description here

This renders a little bit faster than a Glass shader.

It can also help to go into local view (Numpad /)

However, this does not give a black and white result.

If anyone can find a faster method or a way to get a black and white result, please post it :)

Is it possible to visualize ray length info as a black and white map?

2 Answers2

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