Maya Training

Introduction to Hard Surface Modeling

Maya Training

Interiors and Furniture Vol 1 & 2 - Modeling & Cloth

Maya Training

Shading, Lighting and Rendering the Bedroom in MR

Maya Training

Robot volume one - Modeling with animation in mind

Maya Training

Spach-Alspaugh House the complete courseware

Maya Training

Burt The Cartoon Dinosaur Vol 01 - Modeling

New Maya Training

Robot Volume 02 - Hybrid Rigging
You are here > Home > SimplyMaya Community Forums
Loading

Welcome to Simply Maya

Please Sign in or Sign up for an account

Member Login

Lost your password?

Not a member yet? Sign Up!

Old 26-08-2008, 08:33 PM   #1
leonlabyk
Registered User
 
Join Date: May 2006
Location: Hastings UK
Posts: 890
Thanks: 1
Thanked 32 Times in 31 Posts
Default alpha channnel

I am trying to render a scene and need it to clip out my characters in the alpha channel when they walk behind objects in the scene. I have been told this is what I need to do but cannot work it out.

"You will need to Turn the church model into a black
hole matte object so it correctly clips the characters out in the alpha channel and I will also need a
separate shadow pass for your people as well."

Any help with this is much appreciated.

Thanks,

Leon
leonlabyk is offline   Reply With Quote
Old 26-08-2008, 10:10 PM   #2
NeoStrider
Registered User
 
NeoStrider's Avatar
 
Join Date: Jun 2004
Location: Cleveland, Ohio (USA)
Posts: 1,541
Thanks: 0
Thanked 2 Times in 2 Posts
Default

well if it's not a complicated object or if the object doesn't move a whole lot you can just create an animated mask layer in your compositing program to ensure the church shows and the characters 'go behind it'...

otherwise the 'black hole matte' is actually a material. it's called the 'use background shader' and when applied looks green in the viewport. it doesn't show up in renders but shows up in alpha channels, and it still receives shadows from the other objects in the scene.
__________________
Accept no substitutions.
NeoStrider is offline   Reply With Quote
Old 26-08-2008, 10:49 PM   #3
gster123
Moderator
 
gster123's Avatar
 
Join Date: May 2005
Location: Manchester Uk
Posts: 6,300
Thanks: 1
Thanked 51 Times in 45 Posts
Default

Originally posted by NeoStrider
otherwise the 'black hole matte' is actually a material. it's called the 'use background shader' and when applied looks green in the viewport. it doesn't show up in renders but shows up in alpha channels, and it still receives shadows from the other objects in the scene.
The black hole matte is actually in the material attributes, blinn, lambert, phong etc etc, its in the matte opacity tab in the drop down menu.

You also get the option to overide cirtian materials in the render layers so that it does this for the layer its rendering.

You could use the surface shader, but the matte opacity is just the job for this.
__________________
"No pressure, no diamonds" Thomas Carlyle
gster123 is offline   Reply With Quote
Old 26-08-2008, 11:06 PM   #4
leonlabyk
Registered User
 
Join Date: May 2006
Location: Hastings UK
Posts: 890
Thanks: 1
Thanked 32 Times in 31 Posts
Default

Thanks for the advice guys, will give this a go this evening.

Thanks again,

Leon
leonlabyk is offline   Reply With Quote
Old 27-08-2008, 11:15 PM   #5
leonlabyk
Registered User
 
Join Date: May 2006
Location: Hastings UK
Posts: 890
Thanks: 1
Thanked 32 Times in 31 Posts
Default

Ok I have got things working but for some reason the skin is white. I cannot work out why this is and am trying to suss the reason. Any help is much appreciated.

Thanks,

Leon
Attached Thumbnails
 
leonlabyk is offline   Reply With Quote
Old 28-08-2008, 05:40 PM   #6
NeoStrider
Registered User
 
NeoStrider's Avatar
 
Join Date: Jun 2004
Location: Cleveland, Ohio (USA)
Posts: 1,541
Thanks: 0
Thanked 2 Times in 2 Posts
Default

oh hmm never really played with that...
__________________
Accept no substitutions.
NeoStrider is offline   Reply With Quote

A little bit about who we are
Links you might find useful
Catch up with SimplyMaya
SimplyMaya specialises in Maya tutorials. We offer over 1,000 individual Maya training videos, ranging from basic Maya tutorials through to intermediate Maya tutorials. Our tutorials are created by instructors with industry experience and are designed to get you up and running in Maya quickly without making it seem like hard work.

Copyright © 1999-2015 SimplyMaya - vBulletin® Copyright © 2000-2015, Jelsoft Enterprises Ltd.