Vray white enviroment renders grey

[Anonymous]

Hi everyone,

I think I'm missing something with enviroment maps and exposure control. I want my model, which I'm going to animate, to move in full white space with floor and few fornitures. I Thought I just had to place the floor and a white enviroment map, but this way I have no control over the scene lights and the model, which is white too, merge too much with the scene. So I decided to add lights, but this is the result:
https://imgur.com/s1x1Xg7
The background does not exist, but in the rendered it doesn't match the floor
https://imgur.com/xjyRBe0
Same in this second case, there's no light or shadows here
https://imgur.com/0qqCzdG
This third one instead is perfet, if you put the white bg everything is merged, also the eyes (which have self illumination) actually look better. This one is done without any exposure control, the other 2 has the physical camera one. The problem is wihout exposure control and lights everything in a bit bright and the model vanishes in the BG.
Someone can help me set up a scene like that?
I'm using max 2018 and vray 3.6
Thanks everyone and sorry if this looks confused, I'm a bit newbie

[PropChad]

You are heading in the right direction. One of the worst requests I get from clients is when they have a product that is white, and they want it on white. There's a fine line of the product turning out too gray just so you can see the detail, or too white that it disappears into the floor and background.

I leave off exposure control, and do everything in post. Save in a format with a higher bit depth. Like EXR, so you can pull grays out of white without getting any clipping. Set up render elements that you can use to tweak the background separately from your character. The MultiMatteElement is a good one for this. Select your character, right click, Object Properties and give it Object ID 1. When you render, this RE will have your character as pure red. Make your mask from this in your post processing app by selecting by color or channel. Other render elements that will be useful could be lighting, total lighting, shadows, reflection, specular, and maybe even light select. Go through the documentation on Render Elements, and watch a few videos on render composting. There's much more to it than I could write about it here. But it will give you the flexibility to get a beautiful render on white with white parts on your character. You don't necessarily have to do the traditional render comp where you rebuild the render with all the passes. For quick stuff, you can get by with using just a couple passes to tweak your beauty pass. You may even be able to just use levels or curves on your character and/or floor.

[Anonymous]

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@PropChad wrote:

You are heading in the right direction. One of the worst requests I get from clients is when they have a product that is white, and they want it on white. There's a fine line of the product turning out too gray just so you can see the detail, or too white that it disappears into the floor and background.

I leave off exposure control, and do everything in post. Save in a format with a higher bit depth. Like EXR, so you can pull grays out of white without getting any clipping. Set up render elements that you can use to tweak the background separately from your character. The MultiMatteElement is a good one for this. Select your character, right click, Object Properties and give it Object ID 1. When you render, this RE will have your character as pure red. Make your mask from this in your post processing app by selecting by color or channel. Other render elements that will be useful could be lighting, total lighting, shadows, reflection, specular, and maybe even light select. Go through the documentation on Render Elements, and watch a few videos on render composting. There's much more to it than I could write about it here. But it will give you the flexibility to get a beautiful render on white with white parts on your character. You don't necessarily have to do the traditional render comp where you rebuild the render with all the passes. For quick stuff, you can get by with using just a couple passes to tweak your beauty pass. You may even be able to just use levels or curves on your character and/or floor.

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Hello Chad,

first of all I want to thank you for your exhaustive answer, I couldn't expect a better one. I was already planning to set up the render elements, but i did not think it could have helped with the white problem. Just to be sure, correct me if i'm wrong, I have to set up the scene like this:
- No lights in the scene

- White enviroment map
- No exposure control

What I don't understand is how to make my character not merge with the background in compositing. Without any shadow i don't thing that can work. Doesn't masking only the character make it feel like he's not part of the scene or unrealistic? I think I should do some tests, do you think .tga is ok?
If I could see an example of your compositing white on white that would be awesome! But I understand It's asking a bit too much. Thank you for the big help, you're the real Chad

[PropChad]

Light your scene like you normally would. You'll want the shadows, and they'll be needed in the Render Elements. That's the benefit of Render Elements, you can render out whatever passes you need to add or remove shadows. Masking and tweaking the background from the subject is fine, you just can't overdo it, then it will start looking out of place. But it allows you to pull out the whites that are over bright on the subject, so that they don't get lost. A little goes a long way. Make sure your materials for your subject are not 100% white, there is no physical material that is pure white in the real world. This can help get back any detail. Then in post, you adjust your curves or levels until the background just turns white. Then adjust your subject until it looks white, but does not get lost. Practice makes perfect here. Look up samples in image search to see what others have done, renderings or photographs.

TGA might work, I stopped using it after an animation rendered in that format were corrupted some years ago, it left a bad taste in my mouth. I prefer OpenEXR (EXR), set to 32 bit.

One thing to be aware of: If you are not using any environment lights (VRay light set to Dome), whatever color you put in the environment color, will act as an environment light. So if you put white for the background, it will shine white light over everything. This will cause more issues with detail being lost. If you are not using a Dome light, go to the VRay in the Render Setup window, toggle open the Environment rollout, check GI Environment, and Reflection/refraction environment, and set both to black.

I can't show any of my recent white on white stuff, as it is client work and the boss does not like others seeing what clients we have. Too many poachers out there.

[Anonymous]

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@PropChad wrote:

Light your scene like you normally would. You'll want the shadows, and they'll be needed in the Render Elements. That's the benefit of Render Elements, you can render out whatever passes you need to add or remove shadows. Masking and tweaking the background from the subject is fine, you just can't overdo it, then it will start looking out of place. But it allows you to pull out the whites that are over bright on the subject, so that they don't get lost. A little goes a long way. Make sure your materials for your subject are not 100% white, there is no physical material that is pure white in the real world. This can help get back any detail. Then in post, you adjust your curves or levels until the background just turns white. Then adjust your subject until it looks white, but does not get lost. Practice makes perfect here. Look up samples in image search to see what others have done, renderings or photographs.

TGA might work, I stopped using it after an animation rendered in that format were corrupted some years ago, it left a bad taste in my mouth. I prefer OpenEXR (EXR), set to 32 bit.

One thing to be aware of: If you are not using any environment lights (VRay light set to Dome), whatever color you put in the environment color, will act as an environment light. So if you put white for the background, it will shine white light over everything. This will cause more issues with detail being lost. If you are not using a Dome light, go to the VRay in the Render Setup window, toggle open the Environment rollout, check GI Environment, and Reflection/refraction environment, and set both to black.

I can't show any of my recent white on white stuff, as it is client work and the boss does not like others seeing what clients we have. Too many poachers out there.

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Thanks again for all the beautyfull tips here, but I think I'm still missing something. If do as you explained, with lights set up the character it's way better, but the floor merges no more with the enviroment.
https://imgur.com/2lJhPnt
Here my character looks a lot better following your suggestions and now it doesn't get lost in the BG, but the BG is not merging with the floor like in this one down here
https://imgur.com/GXm1lhU
Here I let the enviroment illuminate the scene, as you said is wrong, in fact my character is getting lost into the white, but the floor is exactly how i want it: merged with the enviroment.
I don't know If i'm explaining myself right.
Thank you for your patience and all the help

[PropChad · Accepted solution]

Sometimes you need to cheat things, since the floor is getting the same lighting as your character, that it might not be completely white in your end result. You can fix this in post. Or, if you feel like experimenting you can play with matte shadows. What this does, is it will render only the shadows and reflection of your object, the rest will be transparent. So if your background color is white, it'll render white right through it. In VRay Object Properties, there's some settings in the Matte properties section. I created a quick file for you to look at. Maybe I should have started with this. 🙂 

It was made with VRay 3.7, so hopefully you can still open it.

Edit: Attached example render and alpha from render.

[PropChad]

Here's the render itself. This was quick and dirty, so I wouldn't use my lighting setup here.

[Anonymous]

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@PropChad wrote:

Sometimes you need to cheat things, since the floor is getting the same lighting as your character, that it might not be completely white in your end result. You can fix this in post. Or, if you feel like experimenting you can play with matte shadows. What this does, is it will render only the shadows and reflection of your object, the rest will be transparent. So if your background color is white, it'll render white right through it. In VRay Object Properties, there's some settings in the Matte properties section. I created a quick file for you to look at. Maybe I should have started with this. 🙂 

It was made with VRay 3.7, so hopefully you can still open it.

Edit: Attached example render and alpha from render.

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Why didn't I thought it before?! the matte shadow was the solution all the time. Probably I was convinced it had to be done through the enviroment.
Thank you very much Chad, it works perfectly. I owe you a beer at least!

[Anonymous]

Ehy @PropChad, couldn't find a way to PM you so I gotta bring back this post. Everything we set up here works no more when I use the GPU Render, dunno if you can help me.
Here's what happens at the matte shadow:
https://imgur.com/zimOZ9L (Don't mind the scissors shifted texure 🙂
Tried to fix it removing lights and matte, but we're back to point I see the end of the plane:

https://imgur.com/YRwMOwv
Thank you

[PropChad]

Sorry I didn't see this. For some reason my Thunderbird email client is sending Autodesk emails to the spam folder.

Unfortunately I don't use VRay GPU. But with VRay RT, I know there was just too many things that weren't compatible with the traditional VRay rendering methods, so we just never used it. Not sure if this is one of those things that still hasn't been ironed out by the developers. If you haven't figured it out yet, I'd suggest going to the Chaos Group forums, as it is renderer specific. Someone there should have a workaround to get this figured out.