colour mapping

[jow]

hi,
as i understand you can change the multipliers of the colour map with out having to re-calculating the IR map.
can i change the type of mapping for say Exponential to Linear multiply with out it messing up or is a re-calc ?

[mike.edel]

quote from http://www.spot3d.com/vray/help/VRay...amples_qmc.htm

Color mapping mode also affects render times and sampling quality, since VRay tries to distribute samples based on the final image result.

taking this into account and looking at example3 in
http://www.spot3d.com/vray/help/VRay...vancedimap.htm
there seems to be an influence between color mapping and ir map

normally there would be no samples in very dark areas
if you lighten those using color mapping, more samples are needed - eventually voiding the IR solution

somebody else might know for sure though

mike

[jow]

i see what your saying cheers,
ive ran some tests and doesnt seem to mess up,but id like to be sure..
any one else shed some light on this?

[mike.edel]

probably also depends on the amount of change you apply

[jow]

im making no changes to the scene.
the jobs finished,i rendered it using Exp CM,saved the IR map and was going to re-render using linear CM just to see what the difference was,like you do...

[dgsantana]

i believe that colour mapping is independent. you could try saving in exr and you get all the colour information to process in photoshop, applying there the same colour mapping that you could in vray, so i think colour mapping is just making the hdr information of the image more or less visible according to the options you put in there, and does not affect the lighcache and ir map solution.

sorry the bad english but it's 3:30 am and i'm going to sleep (long job)...

best regards,
daniel

[mike.edel]

the jobs finished,i rendered it using Exp CM,saved the IR map and was going to re-render using linear CM just to see what the difference was,like you do...

that's what i meant with changes
i guess the final image will look different (at least different highlights/shadows)
if your shadows get just a little lighter there might be not enough of a difference to require different ir-map sampling