Explain to me how to get self illuminating ceiling material

[tricky]

We have always used a standard max material for our ceilings in external shots where detailed models of diffuse light fixtures are not required/necessary. This was a simple bitmap in the diffuse slot and then another version in the self illumination slot. It worked fine. Bitmaps below:




However, we are trying to get this to work using a vray texture as we are now using gamma colour mapping which means that the lights don't 'glow'. I have tried many many many combinations of Output settings, Vraylightmtl settings, masks, shellacs, blend materials, vrayblendmtls, etc etc and I can't get a similar effect. Can anyone tell me how to set up a material to get a result?

[Neilg]

How about a mix material between the flat diffuse and a vraylight, with that as a mask?

[Clifton Santiago]

Ah, the old ceiling mapping trick for exterior renderings of high-rise buildings...

When I use LWF with linear defaults (I don't use gamma color mapping), I don't have any problems with any self-illum materials. However, if I add some Reinhard burn to take out hotspots the self-illum parts looks dim. What I do in that situation is make a Blend material, masked to make one material the "lights." Make this light material a VrayLightMtl, and set it of a multiplier of 2 or 3.

As for a literal glow, or specular bloom effect, I just do that in photoshop.

[tricky]

I *think* I've got my head around it now.

LWF - is there a good (short!) thread somewhere as a refresher on how to use a true LWF with Photyoshop CS2 workflow. I remember following a thousand page thread some months ago....

[Clifton Santiago]

See my post in this thread:

http://www.chaosgroup.com/forum/phpB...ic.php?t=17531

You can open .EXR format in PSCS2.