coverage pass

[jumper]

Hi

Any insights into how I would achieve a coverage pass - see ...

http://www.sigillarium.com/blog/lang/en/379/

...in mantra would be much apprecieated

cheers!

Stephen

[Macha]

Either with takes, or with a parameter in the shader network that you then render out as an image plane. I attached the latter as an example.

matte.hipnc

[jumper]

Either with takes, or with a parameter in the shader network that you then render out as an image plane. I attached the latter as an example.

Hey Macha,

Thanks for the reply, but the pass I meant is further down the page and I think it represents the areas of the render where more than one object is contributing to the pixels (as sub-pixels I suppose). I might be wrong ... but that's how I understand it. I have never used it ...it was a request from our friendly compositor.

cheers!

s

[Macha]

Hm, not quite sure.

But try this: set the Pixel filter of the image plane to minmax min and then use the difference of that and the previous pass. It should give you those lines.

[sam.h]

In general you should only use RGB to seperate objects, using more colours will give you funny edges (as you can see on that page, his final comp has weird edges).

[old school]

I wonder if you render with the Wren Output Driver to generate the wires?

[Nerox]

I know what you mean, though I don't know the ins and outs. It's about getting the right aliasing data, there are some tricks where you do some math on aliased and non aliased passes to get the right mattes. It's not about the wires but about how much an objects contributes to edge pixels between objects. Does this ring any bells?

Edited February 8, 2011 by Nerox