Inconsistent defocusAmount on VRayCam?

[biochemical_animations]

My f-number is set at 4. Between two keyframes both set at 4 (animated camera zooming back a bit). I've confirmed that the f-number does not change in between these two keyframes. I noticed some inconsistent blurring on the denoised copy. After checking the defocusAmount pass in the exr render, I noticed there are some frames that are all white, then the proper defocused amount shows up on other frames. I'm using rt gpu 3.5.04. Has anyone else seen this or know how to fix?

[biochemical_animations]

Here is an animated gif of the defocusAmount pass. It is supposed to show a black area throughout, but bounces around from all white to the black being in a different spot...it's all messed up.



nevermind...apparently, I cannot upload an animated gif

[biochemical_animations]

Rendering the sequence through backburner produces wonky defocus which moves all over the place.

Rendering just on my workstation, renders properly.

[vlado]

Can you give me a way to reproduce this?

Best regards,
Vlado

[biochemical_animations]

I'm working on it...thanks.

[biochemical_animations]

Does the VrayCam get it's parameters from max? It acting like this thread here:

https://forums.autodesk.com/t5/3ds-m...g/td-p/5784476

[biochemical_animations]

OK, I just sent you a 3ds max 2016 file to test.

[biochemical_animations]

So, Peter and I have been trying to work on a solution, but to no avail. We thought it might be Backburner, because it only shows up on a network render run through BB. I tried installing 3ds max 2018 in order to update BB to 2018, but the problem still continues.

Even, on my WS only render run through BB it shows up...bouncing defocusAmount pass.

When I render on my WS only, not using BB, the defocusAmount pass does not bounce around and stays consistent as expected. As I workaround I could always render frames that give me trouble like this on my WS only, but I'd like to solve this if possible to better utilize network rendering.

[biochemical_animations]

I've posted a video showing the defocusAmount jumpy on render run thru BB, and defocusAmount not jumpy on render not run on BB run on WS only.

http://www.biochem3d.com/DOF/dof.html

If anyone has an idea I can try, please let me know...thanks.

[biochemical_animations]

Here are a few more AD threads which might pertain to the matter:

https://forums.autodesk.com/t5/3ds-m...6320387/page/2

https://forums.autodesk.com/t5/3ds-m...8576?nobounce=

[biochemical_animations]

Anyway to set the lens breathing for the vraycam to 0?

[biochemical_animations]

Trying the max Physical Camera solved the issue. I was able to get a render thru BB on nodes and ws without the defocusAmount jumping around.

I had been using the vraycam because I experienced fov and focal distance issues with the physical cam when animating, but this is the first time I got an issue with vraycam. I guess I have to switch to the Physical Cam and hope it behaves properly when animating the fov or focal distance.

[biochemical_animations]

In order to get the Physical Cam to match up with the vraycam rendering for a comp, I had to animate the lens breathing from 0.51 to 1.15. Interesting. I'm curious as to what might cause this for the vraycam, since it has no lens breathing setting that I'm aware of.

[Ihno]

Be careful with the max physical cam in animation. I had some bad experiences.
Especially when rendering over BB...
I had jumping cameras and fov animations which didn't get picked up by the render nodes.
I'd highly recommend not to animate the fov (zoom factor or focal length seem to work better here)
And better bake the camera animation to one key per frame before rendering (even if it's a still).

[biochemical_animations]

Be careful with the max physical cam in animation. I had some bad experiences.
Especially when rendering over BB...
I had jumping cameras and fov animations which didn't got picked up by the render nodes.
I'd highly recommend not to animate the fov (zoom factor or focal length seem to work better here)
And better bake the camera animation to one key per frame before rendering (even if it's a still).

Right...I caught your thread over at AD...thanks.

Did you try setting the lens breathing to 0 to overcome these issues?