KeyShot Forum

Technical discussions => Lighting => Topic started by: cjwidd on September 18, 2017, 04:17:09 pm

Title: [RESOLVED] - Light Leaking
Post by: cjwidd on September 18, 2017, 04:17:09 pm
I have a closed convex surface, (e.g. sphere) and I have placed a torus with a light material at the center of that sphere. The sphere contains indentations, each of which share a translucent material. The result is the effect of light diffusing through the translucent surface, etc.

Light is leaking (white pixels) through the surface (see attached). Is there a way to correct this without modeling a shell?
Title: Re: Light Leaking
Post by: Will Gibbons on September 19, 2017, 07:18:57 am
Do they go away if you let it render longer? Also, is that convex surface just a surface? I try to model solids to contain light sources rather than surfaces as they tend to be .... leakier.
Title: Re: [RESOLVED] - Light Leaking
Post by: cjwidd on September 21, 2017, 01:03:25 am
This artifact is a result of a combination of factors, including:
- global illumination samples per light material
- render settings -> samples
- scene units correspondence, e.g. do scene units fit your model?
- translucency, roughness, and bump intensity for translucent material

Render suggestions
- if using material without sample slider (e.g. plastic), switch to a more advance material (e.g. plastic transparent) that does; sample slider can be accessed via small triangle next to roughness slider.
- material samples will often need to be set to 16 or more
- if lighting artifacts are visible, this is likely a result of physical lights in your scene. Physical lights will always take more time to resolve and may introduce artifacts depending on your lighting mode. If lighting artifacts appear, try disabling caustics and switching to interior mode rendering.
- In lighting tab, a value of 4 is generally suitable for 'shadow quality' and 'global illumination bounces'
- In lighting tab, ray bounces will often need to be set to 16 or more