Bright spot, or speckle artifacts sometime occur during the rendering process. Two common causes of this artifact, and their solutions, are discussed below.
Blurry Reflection of Light Sources
This problem is usually associated with interior renderings where the light sources are small. The surfaces exhibiting the artifact typically have blurry reflections. There are three steps you can take to mitigate or eliminate this artifact:
- You can tag the material in question as Glossy in the Material Wizard . This will prevent the surface from having any ray-casted reflections at all and should eliminate the problem and provide better overall performance. Using this switch may cause some loss of subtlety. For many scenes, however, this is not noticeable. It may be helpful to increase reflective Sharpness somewhat after checking the Glossy box. See: Glossy Reflection
- You can tag the material as No Light Source Reflections. This will allow ray-casted reflections, but will exclude light sources from appearing in the reflections. This solution will not improve performance, but will allow the surface to retain more subtle reflections than if you were to use the Glossy switch.
- You can use the Monte-Carlo reflection setting, either globally or locally in Object Properties. This option will be slower and require more processing to resolve.
This problem is typically seen on exterior renderings when the Sun Highlight setting is used. You can mitigate or eliminate the artifact by setting this to a smaller value. See: Sky Setup Tab and Sun Highlight