Friday, August 15, 2008

Gnomon release

The Gnomon Workshop has posted in their "coming soon" section news about the release of my next training DVD. It is called "Multi-pass compositing" and deals with rendering passes out of 3ds max using several different renderers and compositing in Digital Fusion. The DVD mainly focuses on the compositing side of things. I really tried to include as much information as I could. I started off with some basics, but then I got into the "meat and potatoes," if you will, about how to work with passes. I feel that over the years I've come across many compositing work flows and issues in production and I made sure to include examples and explanations on how to deal with as many of them as I could on this DVD. I feel really good about how this DVD turned out. Hopefully if anyone reading this checks it out they'll enjoy it too. :)


Anonymous said...

Thank you for your dvd!
I didn't know that you must perform such operations as unpremult the alphas in vray.
As you focus quite a lot on scanline, it is interesting if you use it often in production and why?
Thank you for your great work.

Tim Jones said...

Thanks for your feedback!

Unpremultiplying is required no matter what renderer your using IF you plan on multiplying any of your passes over another pass (that is also pre-multiplied). You need to un-premult fairly often with Vray and Mental Ray passes because many of those passes are designed to be multiplied.

I think the vast majority of shots I've worked on have needed some un-premultiplying. Most of the time it just because I have an occlusion pass or raw pass that needs to be multiplied over other passes. However, I've also used un-premult to help fix passes that were not matted correctly. Like in the chapter on "basic lighting passes." I've also used un-premult in custom tools I've made for fusion. For example I needed a light wrapping tool that would work in floating point. They way I choose to implement that required an un-premult to get nice edges.

I don't use scanline a whole lot anymore. I mainly use if for rending FX passes and background skydomes/matte paintings. I wanted to include it on the DVD because its a renderer I know everyone has access to. The information that is covered while working with scanline passes carry over to any renderer. I wanted to cover as many bases as possible. So I made sure to include Vray (which has passes that work the same way as MR in Max 2009), and Brazil which is different from all the others.

I'm mainly using Vray and Mental Ray in production now. But I'll still use scanline for some things.

Tim J

Jael said...

Hi, Tim.
Saw all your DVDs - great work!
But can't apply your method, pls help!
I'm trying to use your methods of "lighting" the scene and applying colors in fusion... But getting strange results :(

i got dungeon with 3 torches and green env
rendering 2 passes (torches and env all .rla 32) then seting value in fusion by CC and then seting colour by CG.
flow: BG-Mrg(alpha_gain_0 env_in)-Mrg(same torches_in)-Save
and results looks different then render from Vray...
Vray 1.5, Max 2009, Fusion 5.3
gues I can send you my flow and all you need, if you'll find time to help me
PS: sorry for my english :)

Tim Jones said...

Hi Jael,

I'm not sure from your description what you might be wrong. I'm interested in seeing your two passes and what the result from Vray looks like. Its hard to say from your description what the problem might be, but its seems like a very simple scene since you only have two passes your rendering.

Please feel free to send me an email and attach your passes. I'd be happy to look at them and see if I can figure out what might need correcting.