Global illumination in v ray

[nilariver@gmail.com]

Can any tell what is the role of Saturation, Contrast and Contrast base in Global illumination in V ray settings.

[Ricardo Eloy]

The VRay manual has a fair description of those. Take a look.

[Tim Fairbanks]

http://www.spot3d.com/vray/help/150R1/render_params_gi.htm

 

Chaos Group online docs say...

 

 

Post-processing

These controls allow additional modification of the indirect illumination, before it is added to the final rendering. The default values ensure a physically accurate result; however the user may want to modify the way GI looks for artistic purposes.

 

Saturation - controls the saturation of the GI; a value of 0.0 means that all color will be removed from the GI solution and will be in shades of grey only. The default value of 1.0 means the GI solution remains unmodified. Values above 1.0 boost the colors in the GI solution.

 

Contrast - this parameter works together with Contrast base to boost the contrast of the GI solution. When Contrast is 0.0, the GI solution becomes completely uniform with the value defined by Contrast base. A value of 1.0 means the solution remains unmodified. Values higher that 1.0 boost the contrast.

 

Contrast base - this parameter determines the base for the contrast boost. It defines the GI values that remain unchanged during the contrast calculations.

 

 

To translate all that into real world working terms...

 

Increasing or decreasing the values will increase or decrease the saturation and/or contrast of the GI solution as it is "applied" to the base rendering. Basically, it will produce the same results as adjusting the saturation & contrast of an image in Photoshop, except in the case of Vray, it will do this only with the GI solution rather than the whole image at once.

 

Pushing the Saturation & Contrast values out of a "normal" range can produce some interesting NPR (non photo realistic) effects.

 

TimF