Workflow for Animation with GI in 1.5

V-Ray V-Ray for 3ds Max General
1

Please be patient - I have actually spent most of the day searching for an answer on forum and I cannot find one. The question is about workflow for rendering Irradiance Maps for moving objects. I am familiar with the flythrough method for static objects but I cannot figure out how I use the new Animation (Prepass) and Animation ( Rendering ) settings for Light Cache.

Does the following workflow make sense ?

1. Set Primary Bounce to Animation Prepass
2. Set Secondary Bounce to Brute Force
3. Calculate and Save IRMap
4. Set Primary Bounce to Animation Rendering
5. Load saved IRMap
6. Set Secondary Bounce to None
7. Render animation

Again I’m sorry for asking what seems like such an obvious question - but it’s confusing the hell out of me, and I would prefer to have an idea of what which direction I am going before I toddle off into testing land

Thanks a million as always for you help

2

store direct light - ticked in Light Cache, set light cache to single frame, I believe this is the way to do it with light cache.

3

Great

Thanks for the tips - I did a test yesterday using my theory and it seemed to work great on a simple scene, but when I tried it with a more complex indoor scene I’m getting lots of dancing blotches, I think it might be the low settings I used :

Primary Bounce:

Iradiance Map - Medium Animation
Hsph subdiv - 40
Interp - 20

Secondary Bounce:

Brute Force
Subdivs - 8
SB - 3

Now at least I’ve got a start to experiment with. Now the questions are -

1. If you plan to Glossy Reflections and Motion Blur do you need to have these turned on for the IR calculation - or can you cheat by turning them off to speed up the calc time ?
2. Same for AA settings - should all these need to left at final output final render settings ?

Thanks a million for you’re help

Adam

4

Id say your Hsph subdiv’s are way too low. With only 40 and a Interp(blur) of 20 your not gunna get any nice details. Maybe try more like 80 and see if it helps.

My current exterior animation scene is using 140, 20 for example. The render times will of course go up, but its the price you pay for detail! And its still damn quick against using BF.

5

Is it true that i can render the irradiance animation prepass with multiple computers because they are saved in files per frame?

Before I had to send the irr prepass to one computer because it was multiframe incremental and saved into one file.

6

If it is a static scene (only the camera moving) it’s faster to render every nth frame and then use imapviewer to merge them all together. http://www.chaosgroup.com/forums/vbulletin/showthread.php?t=28569

7

Yeah, that’s what i do with static scenes, except i only use one machine to incremental render the nth frames, so i get one irr file.

In this way i can send the prepasses and the render with dependencies to backburner, and don’t have to merge files together by hand.

But when I have a scene with moving objects the irr map has to be rendered every frame right? So I use the irradiance animation prepass, and get a little irr file for every frame. I can use multiple machines to render these prepass frames right?

8

You can only render for every frame with the animation prepass