High Focal Length settings produces artifacts and errors on high resolution renderings

[frederik_stergaard]

Hello!

I've recently discovered weird artifacts and errors when rendering out high resolution images from Vray.
At first I couldn't understand why it only occurred on a few shots, but apparently it happens when using a high Focal Length number in the camera settings and having a high rendering resolution.
Rendering out the same image in low resolution produces the expected result, but increasing the resolution makes the artifacts gradually stronger and stronger.

As far as i can tell, it produces artifacts on geometry surfaces "black lines" and in the Normals layer.

In this example, i have a Normal image in low resolution, one in high resolution and the Raw result in high resolution.
The low resolution Normal image looks correct, but the high resolution Normal image looks very funky and off.
The cameras Focal Length setting is 2000mm, which of course is unrealistic in the real world, but I can't seem to find another way to produce a isometric perspective inside the VrayCamera / PhysicalCamera.
I assume this is a bug, but is there a way to render out isometric perspectives without increasing the Focal Length setting?


/ Frederik

[vladimir_krastev]

Hi, thanks for posting. I can't reproduce your issues with the high resolution and long lense. Could you share a scene?

I can't seem to find another way to produce a isometric perspective inside the VrayCamera / PhysicalCamera.

Go to the camera tab and switch from default to orthographic. The effect is not visible in the viewport but it is in IPR and production render. It works for the V-Ray Camera and Physical Camera

[frederik_stergaard]

Hi, thanks for posting. I can't reproduce your issues with the high resolution and long lense. Could you share a scene?

Go to the camera tab and switch from default to orthographic. The effect is not visible in the viewport but it is in IPR and production render. It works for the V-Ray Camera and Physical Camera

Hi Vladimir,

I've sent you a PM with a scene were I reproduced the artifacts.
If you make a region render on one of the objects and check the "bumpNormals" layer in the VFB, then you should see the artifacts.
Rendering the image in a lower resolution should produce the expected result, but increasing the resolution should increase the effect.

Hope it makes sense

Also, i tried rendering the image with the Orthographic setting you showed me in your reply, and that doesn't seem to produce the artifacts.
It's only happening when using a high Focal Length setting and rendering in a high resolution

[vladimir_krastev]

Also, i tried rendering the image with the Orthographic setting you showed me in your reply, and that doesn't seem to produce the artifacts.

Yes that is my point. Why not use it instead of extremely long focal length.
With your setup if the camera is switched to Orthographic, the bumpNormals look perfectly fine:

[frederik_stergaard]

Yes that is my point. Why not use it instead of extremely long focal length.
With your setup if the camera is switched to Orthographic, the bumpNormals look perfectly fine:

Hi Vladimir,

Yes, of course i will
I'm not saying that orthographic view isn't the solution, quite the opposite actually.. but that doesn't take away from the fact that it seems to be a bug and i think it's worth for you guys to know

[vladimir_krastev]

it seems to be a bug and i think it's worth for you guys to know

Thanks for bringing it to our attention. We will investigate the issue in more details.