Shadows make objects look "sunken" in to the ground plane

[janstenberg.com]

Hi!

Rhino 8, V-ray 6.
I’m using the viewport to make quick turntable screengrab videos for impatient clients.
I have two problems.

1. It looks like pillars have sunken down in the ground. The problem can also be seen in the ceiling.
   I’ve been poking around with the shadows in the Display mode settings.
   This example is done by everything at its max setting. Not suitable for screengrab speed, but the result is not good anyway. I tried to put an object very far below to trick the shadows, but then it just got very bright below the ceiling.
2. Halos around objects. As can be seen on the right of the sphere on the pillar.
   It looks weird when running the turntable as the “glowy” halo follows some objects/backgrounds.

Ops. Forgot to add the picture.

[Nikolay (Nikolay Bakalov)]

Hi,

Is this V-Ray Interactive Display mode or Rendered display mode ?

[janstenberg.com]

Hi.
It’s a modified version of the Rendered display mode. See the screenshot of the settings below.
Not the raytraced interactive display (real rendering). My graphics card is too slow for making videos in that display mode.

[Nikolay (Nikolay Bakalov)]

V-Ray has nothing to do with the graphics shown in this mode. V-Ray only supplies the textures. The lighting is entirely Rhino’s OpenGL or DirectX graphics pipeline.

[janstenberg.com]

Thank you for clarifying that.
Do you have any idea on what to tweak?
It seems as if I put everything to the max, where I could find it.

In the OpenGL settings, I have Antialiasing 8x. GPU Tesselation checked, (Max OpenGL Available)

Video Hardware & Driver Information:

NVIDIA Corporation
NVIDIA GeForce RTX 4070 Ti/PCIe/SSE2
OpenGL version: 4.6.0 NVIDIA 551.23
Render version: 4.6
Shading Language: 4.60 NVIDIA
Driver Date: 1-18-2024
Driver Version: 31.0.15.5123

Maximum Texture size: 32768 x 32768
Z-Buffer depth: 24bits
Stencil depth: 8bits
Maximum Viewport size: 32768 x 32768
Total Video Memory: 12 GB

[Nikolay (Nikolay Bakalov)]

Can’t say for certain, but it looks like bad ambient occlusion.
How does standard Rendered viewport look like ?

[janstenberg.com]

Standard:

Max:

Standard:

Max:

Other settings…

[Nikolay (Nikolay Bakalov)]

I don’t think you can do something. The shadows in Rhino are simply not good, even in 7:

I’d rather move it out of the V-Ray section into a more appropriate one, so that McNeel devs could see and response to it.

[janstenberg.com]

Thanks.
How do I move it?

[nathanletwory (Nathan 'jesterKing' Letwory)]

You don’t have to, it already has been by helpful moderators.

[BrianJ (Brian James)]

Hi @janstenberg.com ,

With regard to skylight shadows in Rendered mode. I filed this request a long time ago https://mcneel.myjetbrains.com/youtrack/issue/RH-30310 for a distance slider that I think would help in cases like this. Without that ability, I would use a reduced shadow intensity in Rendered mode as well as a lowered Skylight intensity while using the Sun or another light source for directional shadows.

[Jarek]

Check this out:

[Feature request] Arctic "occlude behind object" setting/slider

My understanding is that in Rhino the Screen-Space AO uses some ZBuffer-driven trickery and not what the “Dirt” material in rendering engine does. It probably comes with some limitations so it may be hard to expect for it to be perfect (but always worth trying!). It has already improved a lot since its introduction in earlier Rhino versions and works very well both in Artic or as a Skylight Shadow in other display modes. One thing to note is that somehow in Rhino the “radius” of the AO is relat…

[janstenberg.com]

Thanks Jarek!
Thats very useful!
Quite an improvement, I would say.
Some more tweaking and testing could be done, but just a fast test. Excellent!
I would say that you solved the problem.

Maybe something for the McNeels to incorporate?

Thanks again!
Jan

[Jarek]

@janstenberg.com

Maybe something for the McNeels to incorporate?

It would be great but if you look at it its highly unpredictable as it depends both on camera lens and also target distance… That’s probably why it stays as a test command so far.

But I can imagine this: have sliders for radius (0-10) and intensity (0-10) exposed in UI.
Also please have these settings remembered in the document. @DavidEranen @jeff

[janstenberg.com]

For my setup, Rad 15 (!) and Int 2, gave the above result.
However, I have a huge background cylinder as a backdrop, which may affect the result.

[Jarek]

Yeah, it really depends on each file and specific camera. And I forgot, only the intensity is limited 0-10, radius can be anything, so not very slider-friendly, it would need to be a value box with arrows in UI : )
I am glad it worked out for you though as-is with the test command.

-j