Diffuse color can't be multplied above 100% and no HDRI textures at 1.5?

[Micha_cg]

Hi,

I reported it as bug ticket 8164, but I'm not sure, it's a limit of 1.5 that stay. So I'm very curious to know more about it.

At 1.05, if in darker areas of the scene the white was looking grey, I used the acolor with a multiplier above 1 to get the wanted white look. That's not working at 1.5 the moment.

At 1.05 I used a "full HDRI" setup, where the HDRI was used as ground texture and as background, both perfect matched per env mapping. At 1.5 HDRI textures are clamped, the setup can't be used at the moment. Attached an example what was possible - no seam, no cut visible at the env and the reflections.

I hope someone of the Chaosgroup team can tell more - is it a bug that can be fixed? I hope so.

++
Micha

[Svetlozar Draganov]

Hello Micha_cg,

Could you please send us an example scene with HDRI setup including HRDI maps to vrayrhino@chaosgroup.com.
We would like to test it in our environment.

Thanks in advance.

[Micha_cg]

It's bug case 8164. I posted here because I would like to talk about it. I hope it isn't a new "feature" that diffuse colors can't be multiplied above 1 and HDRI are clampled. I sent an email with example. Could it be fixed fast as possible please? I need it at my current project, where I use 1.5.

Attached two screenshots - 1.05 vs. 1.5

[Svetlozar Draganov]

Hello Micha_cg

Thank you very much for your feedback and for the examples.
I couldn't give you a time range about when this will be fixed - our developers are constantly working on such a issues , but sometimes it could take a while until the bug is fixed.

Thank you very much for your patience.

[Micha_cg]

Diplomatic answer - I wished I would be a hobby user only.

[joe_b]

We talked via email, but in case anyone else is curious about this- the brdfs clamp colors before working on them. This change happened shortly after our old VfR (1.05.29) was released so that is where the difference is coming from. The only brdf I'm aware of that does not get this clamping is the emissive layer.

[Micha_cg]

This means at 1.5 HDRI textures can't be used for full-HDRI-Setups, where a ground and the env share the same map and perfect match. Simple setups a la keyshot are impossible at 1.5.

Here an example scene for Rhino 4 and VfR 1.05:
www.simulacrum.de/download/FullEnv.rar

The result at the screenshot can be reached per full res HDRI, at the downloadable example only a low res version of the HDRI can be found (original size was 150MB).

General it should be no problem to get full env working easy to use like at keyshot, the path setup could be easy automated - the user select a HDRI and GI/Background/Rhino background(R5) could be automatic set. In my example there is a layer "Environment for Rhino Display". Here is a JPG version of the HDRI assigned that match the Vray render. So, the Rhino 4 viewport can be used to see the environment at the viewport.

Basic requirement for this simple full environment - no clamped HDRI!

[joe_b]

Here an example scene for Rhino 4 and VfR 1.05:
www.simulacrum.de/download/FullEnv.rar

Thanks Micha, I'll check this scene out. It seems to me there must be a way to accomplish your goal - HDRI setups are very common and I'm pretty sure the clamping you are pointing out has been in all the V-Ray products for a few years now. I'll get with Fernando to see how HDR setups are done in the other products ( Max, Maya, etc ).

[joe_b]

It seems the correct workflow to accomplish what you are trying to do requires the VRayWrapperMaterial. I'm working on bringing that functionality over.

Sorry for the inconvenience

[Micha_cg]

I tested the Wrapper material and it works great, no need for soft edge transparency to match the ground material with the background.

A little wish - please set the default values so that it take the env as texture. I hope my settings at the screenshot are all right.

Should the matte workflow not allow to get an alpha channel with shadows? I get the standard alpha look only, the ground plane show no shadows at the alpha. Did I something wrong?

Thank you for the adding this tool!

[Dana Arts]

I'm semi new to Vray for Rhino and would love to understand this process. Where do I find or how do I make a Wrapper material?

What is the matte workflow. I don't even see those options.

How do I extract the shadow in the vfb channels (shadow). I just get black and the alpha doesn't show any shadow.

Would love it if you could shed some light on the subject. Thanks

[Svetlozar Draganov]

Hello Dana Arts

Wrapper Material is available in Vray for Rhino - Nightly Builds - it is not released into Vray Official version.
If you have access to the Nightly Builds section - please log in and download the last Vray Nightly Build - if you haven't please write to support@chaosgroup.com and request access to the Nightly Builds Section.

Raw Shadow Render Element is black and white image where the white represent the shadows - and the black represent the illuminated area.
This render element could be used in compositing software to adjust the amount of shadows - the workflow is to invert the image and then to use "multiply" blending mode.

[Dana Arts]

Thanks, I'll look into it.

You know there should probably be a separate section in the v-ray for rhino part of the forums that is for the beta testers. That way no one confuses the newest version and the beta versions.

[Micha_cg]

I posted it here, because it was a 1.5 limitation that was not at 1.05, but you are right, there is a beta section.

[kostenurka]

thanks a lot for Wrapper Material
It takes off 10 kg. from my daily backpack

works great!
cheers