Vray and RPC - Migraine Inducing!

[womble]

I'm trying to render a few short scenes for an animation at work. They are adament that we have all sorts of RPC's in the scene (trees and moving people etc) but I'm having some quite major problems incorporating them.

 

I'm using Vray 1.46 by the way.

 

1. I was trying to precalculate both my Primary Irradiance map (set to 'Low' settings) and Secondary Light Cache every 10th frame. When I tried to do a test render using these files the RPC's sporadically dissapear from random buckets. For example, the head of an animated character will render, but the body (in a different bucket) will fail to render. There is no error message in the vray log window. All RPC's have reflections and shadows turned off. All RPC's are excluded from every light source in the scene. When I render the scene, recalculating my irradiance maps and light cache every frame the problem seems to go away (much to the dismay of my total render time and looming deadline!)

 

2. All RPC's seem to have an issue with appearing behind glass. Looking through a window to some tree's on the outside they appear as white rectangular billboards, the same tree is properly rendered in an area of the scene that is not behind glass. The windows are set up as 2 planes, 5mm apart and with flipped normals so that the front side faces outwards. They have a refraction setting of around 247,247,247, very minimal reflection (might be none, can't quite remember), and a slight fog colour (to give a green tinge to the pane). Incidence of refraction is something like 1.6 and there is no problem rendering other geometery through these windows.

 

Any advice on either problem would be much appreciated!

[Trevor Tizard]

I gave up trying to use rpc's in my scenes some time ago for just the same reasons. If I really need them I'll render them separately with the scanline renderer and comp them in after.

 

More work I know, but will get the results.

[womble]

Could you maybe give me an example workflow for that workaround? The rpc's are sometimes obscured by geometry and I can't get my head around how to accomplish that.

 

Is it a case of:

 

render the flythrough without the rpc's

change all materials to basic matte scanline materials (without maps and bump maps etc)

render flythrough in scanline without GI etc. What other fields do I need to render out in order to comp them together? MaterialID or something?

comp together in combustion?

 

Thanks for any help

[womble]

Well fixed the second problem! Seems for some silly reason I had turned off 'visible to refractions' in the object properties box for all the rpc's. Think I probably did this trying to fix the first problem and forgot. Ah well! One down, one to go!

[aaron-cds]

Are you aware that many of the rpc problems have been fixed with the current 1.5 release, which is free by the way?