Converting normal pass to speed pass to make a trick

Support Compositing and Post Processing
1

Somebody can make a node setup that converts the normal pass to speed pass?
I want to try my idea to make a fake GI trick with this. :slight_smile:
Or is is not possible?

My idea:

  1. converting normal pass to speed pass
  2. using vector blur making a pass that blurs the lights along the normals - we must use zbuffer somehow to avoid the blur of the distanced objects (maybe using bilateral blur?)
  3. using this fake light pass we have a very fake GI thing :slight_smile:
2

Excuse me, but what do you mean by speed pass?

A very very fake GI can be obtained by a diffusely convolved cube map. Have you tried that?

3

Oh my, I should have googled it before asking…

http://www.blender.org/development/release-logs/blender-242/vector-blur/

4

Have you seen some of the faked sss?
In yafaray to get a cheap fake sss you use the enable vcol light,
there’s probably a way to make the lights intensity raise based on
an empties direction from the light? Yafray vcol sss looks terrible though.
Vector blur takes a little bit to calculate,
although it’s a lot faster than regular blur, but I couldn’t imagine being able to play anything
while blur was running at the same time. My computers pretty old though.
http://tgeaenhanced.blogspot.com/2008/09/skin-shader-subsurface-skin-scatter.html

5

No, I need that I have write in first post. :slight_smile:
But thank you for the answers.

And speed pass sometimes called vector pass in Blender. :slight_smile:

6

I think you need to enable speed for vector blur,
I figured that was half of what vector blur was, so I thought it might turn out a little slow.
mpan made a realtime ao fake somewhere, I forgot about that :smiley:
I’ve seen a few threads where the person is trying to figure out an updating render to texture python script,
and I thought it was for render and not game, but who knows? :smiley:

7

Somebody can help?

8

Hi endi,

Have you heard of this being done before? Have you made any attempts at this yourself to show (even failures)?

9

I am not a great node wizard, so I cant make tests. :slight_smile:

10

Ok, fair enough. Can you explain why you think this might work?

11

You can’t do this. The two passes have absolutely no similarities. The colors have completely different meanings within the passes, and the Vector pass contains an alpha where the Normal pass does not.The best you can do is plug only the specular pass into the vector blur node. It will need to have an alpha channel so plug it (spec pass) into a set alpha node (both sockets) to give it an alpha proportional to it’s brightness. Other than that I believe you’re out of luck.

12

Actually, you can do that:

You’ll need to understand what the individual color channels in the “Speed” and “Normal” pass mean though. The Normal pass simply contains the components of the normal vector in RGB, that is R is X, G is Y and B is Z. The Speed pass contains the previous and next position in screen coordinates relative to the current pixel in RGBA, R is previous X, G is previous Y, B is next X and A is next Y. So you’ll need to convert the normal coordinates from world space to screen space, which is not simple in nodes, though you can probably do a good fake of that transformation with a couple of “Normal” nodes. I don’t think the basic idea to use that as a fake GI method is very helpful, but I could be wrong (is this used anywhere else?).

HTH, David.