RPC Question...

[sutaih]

Is it possible to apply a matte shadow material to RPC objects?

 

Thanks

[Tommy L]

i dont think so, but there is bound to be a work around. could you be a bit more specific in why you need this?

[sutaih]

It's kinda complicated with how I got here. I'm working on an architectural animated scene and I'm using VRay as my lighting plug-in. To use VRay efficiently, I must bake the scene every Nth frame and save that irradiance map so the scene never has to calculate light when I animate.In this case, I'm calculating every 20th frame out of 700 and it's working out just fine.

 

The complication is that I am animating cars and people in the scene. If I understand this correctly (be it that I am still very young and terribly inexperienced at this), I must bake every single frame to get correct shadows, etc..., but I simply don't have the time or hardware to accomplish that daunting task. So I figured I would composite the animated people in post using matte-shadow materials on all my geometry in a separate file and if I do this, I can even use the scanline renderer to cast shadows in the right direction and be "close." I've gotten this far and it works really well and no one would ever see that I fully composited the animated objects - except where the RPC trees are located. So, I simply need to know if there is a way to apply a matte-shadow material to the RPC trees and I would home. I've tried several "work-arounds" but I have been unsuccessful thus far.

 

I hope this post makes some sense and I'm keeping my fingers crossed that someone out there might have an answer for me.

 

Thanks again...

 

...moderators: is this a better question to ask in the VRay forum?

[Matt McDonald]

I don't think so. But I think that you are trying to composite your RPCs in post and thought I don't have a lot of experience doing this I think that the thing to do is to assign a G-Buffer or effect channel ID and then add a "matte" pass based on that ID in the render elements. The matte pass will give you a mask for compositing your RPCs even with things placed in front of them.

 

Good luck, it sounds like fun.

[Tommy L]

it sounds like you have your moving rpcs in a seperate file to your trees? Cant you just puit your tres in the same file as the cars and people?

[sutaih]

I'm not using moving RPC's - only still trees. Everything that I have animated are 3D components.

 

Designmule - I didn't realize I can apply an effects channel to RPC's. I 'll definitely look into it.

 

I think what we're going to do is basically fake the RPC trees by tracing them at different angles with splines and applying a matte-shadow to the new object (the trees are palms and are fast and simple to trace). Now I know that doesn't sound like a good solution but for what we're trying to accomplish, the results work out. The trees are far enough away from the camera that we'll be able to get away with it. Basically the people in the scene will look like nothing more than ants walking around the trees. So if anyone else has any other solutions that are better than mine, let me know!

[Tommy L]

what version of vray are you using? If its vray 1.5 you can render the trees as a sepererate channel.