View Full Version : Poly as IBL in vray
01 January 2012, 12:46 PM
Hi everybody !
I am rendering a animation with vray with a sphere poly as IBL, but i got flickering in my animation, so i wouldlike to kno if there is a way to avoid them by adding sample to the sphere like in the mentalray tab parameters but for Vray.
The dome light dont reproduce the same lighting.
01 January 2012, 01:59 PM
Are you using a high resolution HDR image for the lighting & reflections ?
01 January 2012, 02:25 PM
Thx you for reply,
Yes i am using a 2k texture with my sphere as IBL the shader is a simple surface shader.
i used a second shader(vraymtl) for the Gi of the surfaceshader, it seem to give better results but i dont kno if it's accurate enought because i can't see a way to control the sampling.
01 January 2012, 02:34 PM
Rule of thumb, high resolution image for your environment reflections, low resolution diffuse convoluted (diffuse_sh plug in for picturenaut http://www.hdrlabs.com/picturenaut/plugins.html ) image for the actual lighting. It needs to use averages, not pixel point interpretations of light.
For example, try out sIBL (http://www.hdrlabs.com/sibl/index.html), and you'll see it'll have two sphere's (depending on renderer) usually, one for high res reflections, one for low res but lighting.
But pretty much using a high resolution image is going to cause problems in an animation.
01 January 2012, 04:54 PM
Nice plugin thx you so much for the link, i ill try this out ;)
01 January 2012, 09:03 AM
So are you using a sphere with an hdr texture and then using GI to calculate the lighting from it?
If so this is why you are getting flickering.
You should substitute this lighting method with just using the vray dome light.
You can connect you hdr to you dome light and it will emit direct light from it (via importance sampling, so more sampling around hottest points in hdr resulting in good shadows) and will produce no flicker problems.
01 January 2012, 09:18 AM
yep what chuckie said - vray dome light is the way to go.
Just use one high res HDR image in the dome light, it will handle the rest internally. And it will be more realistic too. There is a vray video about it - http://www.youtube.com/watch?v=EvBffTQ29LM&list=PL11E91582A45B7CD0&index=3&feature=plpp_video
01 January 2012, 09:36 AM
He said the dome light wasn't working properly for him.... ;)
01 January 2012, 09:36 AM
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