Logarithmic Exposure and Reflection conflict

[Cocytus09]

Does anyone know how to get the reflection of the Background Image on a raytrace chrome material to show when using Logarithmic Exposure Control for exteriors?

 

I'm attaching a picture of a chrome sphere lit by the daylight system. One doesn't have the exposure control applied and the reflection of my background sky is visible on the sphere. The other pic has the Logarithmic Exposure Control applied and the sky disappears. Any help is appreciated.

 

Thanks.

[abicalho]

I can only guess you're using VIZ 4, since this was changed in VIZ 2005.

 

Increase the exposure control to match the brightest light source in your scene. This will ensure reflections and self-illumination objects will render correctly.

 

Alexander

[Cocytus09]

when you say "increase" the exposure, do you mean the physical scale? brightness? how do I increase the logarithmic exposure?

[Ivan Pajares]

Check the intensity of the background sky map. If it is non hdr you will have to increase the output levels (in material output controls) so that it becomes brighter and reflects on the sphere. Take on account that if you use 'real' or photometric lights, you would have a virtual light with an equivalent multiplier of, let's say, 50 or 60. If your background map is non hdr and correctly exposed its whites would be thousand times less brighter than the light source, making it virtually black.

You have to balance the whitest point of your background maps with the lights you use. Logarithmic exposure can help to bring the gap closer between bright and dark objects, but can't do miracles.

 

Good luck.

[abicalho]

I meant Physical Scale. Sorry.

 

Alexander