Logarithmic Exposure Control

[chicoone]

Could I please get support for Logarithmic Exposure Control on a per object basis? I got some use for that.

Thank ya,

Ismael

[evelyn]

If yes, also separate the Environment from Max exposure too.

Regards,

Evelyn

[cpnichols]

Not that I would want to say how to do your work, but generally speaking something like this would be done in composite (or photoshop for stills), where you would create a matte for that object and use the matte (or object G-buffer) to control the color and exposure of the object after the render.

For the actual render, keep it as "real" as possible.

[evelyn]

Ok, you are from Lalaland and are talking to me about "real"? Could you expand that quote for me? What do you mean?

So you and others would not be left wondering what "unreal" is that am working on: I import a Lightscape lighting solution to Viz and Vray respects the lighting from LS. Cool! Problem is the lighting comes in a mesh with a Lightscape Material that has a Standard material as the sub-material. If I replace the Std with a Vray mat the object gets too dark and only way to lighten it is to 1) blend or shellac with standard mat. 2) Turn on Logarithmic Exposure control from Viz 4.

Now everything should be ok with #2, except that Vray is using the Logarithmic Exposure from Viz over everything including the Max Environment Overrride switch.

Also if I need not post-process why would I?

Thanks for taking the time to read the post and contribute. Please do not take offense of the joke I made about where you live and I hope all the Lala people are doing well.

Cheers,

Evelyn

[cpnichols]

Ok Evelyn... you did not offend me with the lalaland joke... just a few things I would need carified before I can explain myself.

It looks like you are trying to take a lightscape model and rendering it with Vray. Vray does not respect the lighting, it is just that the lighting is burned in.

Are you doing any GI in Vray? If not, I would urge you to dump LS, and use Vray for your GI. Otherwise, just use straight MAX.

What I mean by "real" is do the more obvious solutions, if an object looks too dark, make it a brighter material. If a scene looks too dark, brighten the lights, if the floor looks too red, make it less red. With all the lighting and exposure controls, people tend to miss the obvious sometimes.

More on exposure and post process once I get a better understanding of what you are doing.

[chicoone]

Cpnichols,

I will not dump LS. It cost me $540 and it is still a quite capable venue. Have you seen the work of Chen Qinfeng? Check the interview on Evermotion's front page. There he mentions he will be using Vray in more depht in the future.

The topic of using a Lightscape solution has been brought up many times on this forum and others:

http://www.chaoticdimension.com/foru...ght=lightscape

Vray now has support for Log Exp Control and that just opens new doors since it allows the lighting of the mesh to show through. Having worked with LS and Viz 4 and gone through a lot of reading on "physically based.." I would like to see some lighting analysis tools being implemented
in Vray. One Matty guy stated once on this forum that IES distributions were just for show! Take for example a fluorescent fixture with 2, 3 or 4 tubes; how do you make that with Vray lights, just to get the right intensity? Just recently Vlado put together some formulas. Saw them at Vray.info That is what IES distributions are all about. They have not only the luminaire intensity but also takes into account the physics of the fixture and or lenses. But that is just another subject.

I am running too lenghty on this and after all this is the Wishlist section and I just posted a wish. Thank you for the Vray tutorials offer. Right now I don't need a tutorial but I hope the offer still stands when I do.

Regards,

Ismael

[cpnichols]

Ok so let me get this straight..... you are not using any of the GI capabilities of Vray, only using it for the actual rendering, and doing all your GI in lightscape. Interesting...

From my understanding, the exposure control was a replacement for the LUT control (pseudo exposure control) that was built into the Vray. Why built it twice when you can reuse what already exists... but this has nothing to do with supporting radiosity mesh from lightscape (in vray)... it has to do with getting a LUT out of Vray's GI. The IES lighting support of Vray is based on its ability to read the proper falloff, and again has nothing to do with the GI calcs in LS.

Your process, while interesting and valid, seems to have nothing to do with the way Vray is supporting IES or exposure. I would say, if you are doing your GI in LS, what are you expecting out of Vray? Can't you do most of what you want out of Max? Nonetheless, I can see youre need for Vrays faster raytracing (for reflections etc...) so... to be long winded, your wish, is a vaid one... just odd to me (keep in mind I come for the VFX world).