PDA

View Full Version : VRAY self reflection cutoff bug??


Gal
07-01-2010, 06:20 PM
strangest most simple issue yet unsolvable in both may and max.
follow this:
new scene, create pipe.. give it a fully reflective blinn or vrayshader (fresnel off). create a sphere with solid color to be reflected on the pipe. render.
the inside of the pipe will render BLACK and not the blue env that should bounce inside the pipe/be reflected.

all samples increased in raytrace ray count of both the shader and the globals to 20. all normals are facing the right way.

I've attached an image to show what i mean. ignore the back part as it's single sided i just mean the center of the pipe with the correct normals(altough double sided, flipping normals also has the same effect, it's not a normal issue).

IF you disable the object visible in reflections and the env passes through the object, it reflects the blue inside.....so... the object self reflection blocks the reflection and perhaps limits the reflection bounce to 1? even though it's set to 20! i dont understand this issue. same exact error happens in new fresh scenes in different computes in both maya and max! (both 2011).

this cant be a bug since this is so basic and no one would work with such a limitation. must be us, any ideas what we missed?
thanks

thev
07-01-2010, 10:30 PM
Are your normals pointing in the right direction? Try turning on the "reflect on back side" option in the VRayMtl material and see if it helps.

Best regards,
Vlado

djx
07-02-2010, 04:40 AM
Not a bug. This is expected behaviour for a pipe with a perfectly reflective surface that is closed at one end. The faces that are black are reflecting the inside of the pipe. From the viewpoint in your image your 20 bounces would not make it out of the pipe to see the surrounding sphere. Rotate your pipe (or your camera) and you'll see the inside of the pipe reflecting at various angles.

David

CGTalk Moderation
07-02-2010, 04:40 AM
This thread has been automatically closed as it remained inactive for 12 months. If you wish to continue the discussion, please create a new thread in the appropriate forum.