Multipass render to layered PSD file

[Nickh]

thanks. I'll give coverage a go

do look at scene states. They are pretty handy - they remember vray properties too, so as well as object channels you can have multiple matte passes all setup to render to differenet outputs in one max file.

andrew - how do you give diferent materials different alphas in max?

[mike.edel]

thinking about another approach right now:
using a layer manager like blur's onion you can specify a secondary material per layer
so you would seperate all objects on different layers, assign the secondary material (self-illuminated white on black background) and render them with vray
you would get antialiased object channels

should also be possible to do this via scripting (f.e. using the object's layer to determine if its visible in the pass)
it should even be possible to script-render multiple alpha channels into one tif file (afaik both max and tif files support multiple alpha channels per file)

[sjmoir]

Interesting thread. If I need a perfect mask I apply a black standard material to everything, white 100% illuminated standard material to the object(s) I want to mask. Then turn off all lighting for a fairly quick and perfect mask. I looked at PSD manager, Combustion etc but ran into AA problems (eg for subtractive AA methods Cat-Rom etc).

[panthon]

Using all the methods mentioned earlier, you would end with a solid colors image, which would be easy to use in photoshop and even more efficient in combustion: using a gbuffer builder you could point and click your object and get an instant selection.

Don´t you think vray could render a solid color pass based on ids at the user demand and embed it on vrimage or rpf? This would be very fast to render, without gi, reflections, refract, all off, except displacement maybe. This way would be a workaround to get the perfect masks we're looking for.

[3ddesign]

Interesting thread. If I need a perfect mask I apply a black standard material to everything, white 100% illuminated standard material to the object(s) I want to mask. Then turn off all lighting for a fairly quick and perfect mask. I looked at PSD manager, Combustion etc but ran into AA problems (eg for subtractive AA methods Cat-Rom etc).

How do you prevent the black halo around your white object created by AA? When you select in PhotoShop, do you expand your selection, feather, etc.?

Craig

[sjmoir]

3ddesign: In Photoshop, go to Layer/Matting/Remove Black Matte

[vlado]

In recent builds V-Ray can output the wire color of objects into a separate render element with or without antialiasing - in this way you can specify the exact colors that you want for masks.

Best regards,
Vlado

[3ddesign]

3ddesign: In Photoshop, go to Layer/Matting/Remove Black Matte

sjmoir,

Thanks for the great tip. I've never seen that before. Sure will make things easier from now on.

Craig

[jacksc02]

oooo thats good news vlado!