Rpc

[Trevor Tizard]

Hi All,

 

I've recently purchased Vray Advanced and have some issues with RPC people, trees and cars. In most insatnces they simply don't render although I've seen a couple of scenes in this forun that appear to include them. Are any of you using rpc's and if so are you rendering them separately with the scanline renderer?

 

Any asistance would be much appreciated.

 

Trev.

[karl zacharias]

don't think they work in vray...i do most of them in PS

[frank1331]

Not sure about Vray advanced, but they do work in the free version, so they should work.

 

By default they seem to be excluded in the light, so you need to goto the light and make sure they are included, also check the properties of the RPC to make sure they are visable to the camera.

[cH1ooo]

they'll work, but make sure also to reduce their "self illumination" that can cause splotches otherwise... better still is post work...

[Jeff Mottle]

I spoke to the guys at work and they say they should work ok with V-Ray. There is an issue with reflections as well as with cars on occasion causing colored dots.

 

The reflections issue workaround is: If you enable cast reflections it will not work correctly as V-Ray is not able to properly calculate one sided materials. If you disable reflection casting it will still cast a reflection but it will always be the same image facing forward.

 

 

The cars issue workaround is: When I ran into this issue I was able to fix it by converting the car materials from standard to vray materials.

 

 

If you guys do have problems other than this, you can contact Jon our support guru. He'll be able to help you figure out the problem and hopefully find you a solution or workaround for you.

 

http://www.archvision.com/Support/TechSupport.cfm

[Christopher Nichols]

To be really honest, trying to render RPC (a self illuminating object) into a rendering which calculates global illumination, is going to be an issue. Sure there are work around, but they are a pain to deal with IMHO. I would suggest, and this is something I used to do when I worked with RPC in the past, is to render them in the scanline rendering while making the rest of the geometry a matte to hold it out. They will render super fast (as in a matter of seconds). You can easily place them around your scene that way and adjust them. You then comp them in (A over B). Works well for stills and for animations. That way, if the client/architect wants to you move a car (which seems to happen more then actually fixing the bad architecture), it is a matter of seconds rather than wait for a whole new render.

[visions]

Hi Chris,

would this work even if the self illuminated content was in the foreground and background too, and the structure in the middle

could you please give some more information on sucessfully compositing for Stills and animation, using Max or photoshop.

Thanks

Vivek

[Tim Saunders]

I know your question was directed to chris, but the answer is yes. Asigning a matte material to everything other than the rpc's is different than only rendering the rpc's. All the geometry is considered when matte material is used, it is just rendered as black. So when geometry passes in front of an rpc (or any other "non-matte material object") you will see the part that passes in front as black. You can then change the blending modes in ps so the rpc layer lays properly on top of the scene layer.

[Clifton Santiago]

RPC works fine in Vray 1.47.03. As Jeff mentioned though, there are strange lighting artifacts that can occur with RPC cars.

 

The best thing I have found to making RPC people work in the scene is to have them cast real shadows. To do so make sure they are not excluded from the lights, which happens by default. The RPC cast shadows option has no apparent effect.

 

The real problem with RPC though is they don't look good. They are fast and convenient when one needs to give a draft render some scale, but there are better options. Using quality people photo libraries (such as Dosch or libraries from Turbosquid) combined with a billboard plugin like ItooSoft's Forest Pro can give much better results than RPC.