reflection dimmed by smooth texture

V-Ray V-Ray for Maya Issues
1

Hi all,

I have a problem that I never encountered and which is getting me mad.

I want to have a white ground with black surrounding. The white area should get reflections, etc.
The camera is rotating 360° around this area.
I made a material where color, reflection color, reflection color amount are blended with a smooth texture. The scene is lit by a Studio HDR.
everything works fine unless the hotspot of the HDR (the fake reflector) is not directly reflecting in this ground. When this happens I suddenly get a sharp edge between the (white) reflective and (black) non reflective surface.
I tried the same with a blend material. I tried also with a simple Vray rectangle light.

If it’s a limitation, can you please get me a workaround ?

see attachements…

best regards,

olivier

Maya 2012 + Vray build 22281

halo2.jpg
halo2.jpg600×338 14.7 KB

halo1.jpg
halo1.jpg600×338 18.5 KB

mask.jpg
mask.jpg600×600 17.6 KB

2

reflection or light cutoff? did you try that.

3

Oh thanks Dmitry, cutoff threshold does the job (at 0.001).
I didn’t even ever notice this param… what is it really for ? I’d like to know… why is it at 0.01 by default ?

best regards,

Olivier

4

its an optimization feature, so no reflections get traced when their threshold falls below specific value. If you have a scene which has low frequency (dark reflections) and also gradient reflection/lighting, you really need to set that value that low.

5

Dmitry,

Thank you very much for this explanation !

best regards,

Olivier