multipass or object buffer?

[jondoe0ne]

hello,

i am currently using vrayforc4d DEMO and i would like to know how to set up correct multipass. essentially what i need is to be able to change an object texture from a scene without rendering the entire scene all over again and then crop the area i need in PS (e.g.: a house with different furnishings and colours on the outside, that allows the client to test different materials on the same scene with little worktime). this is an assignment my boss wanted me to resolve as he is interested into buying vrayforc4d but he doensn't want to throw away his money for a product that isn't suiting our studio's needs.

i have done an extended search on this forum and found nothing about this subject, as this is a serious matter for us and buying the software depends upon us being able to do this kind of work with this software.

thank you in advance.

[KKL]

from what I understand it's just adding the normal multipass in C4d, then add what you need under multipass in Vray, basically add diffuse-multiply,raw light,ind.ligh (like in Photoshop), then add specular and reflec and whatnot, (though when I do this I end up with a weird diffuse channel image, so multipass is probably not supported in the demo)