Physical camera and motion blur

[SonyBoy]

When using the Vray physical camera, the attributes in the moblur rollout of the Overrides tab in Render Settings have no effect, or at least that's how it seems.

This being the case, are there any means for controlling similar effects such as bias and blur center? I am currently working shots where I want to use the physical camera, but also have the ability to adjust these effects as I am getting strange offsets with the live action I'm matching to.

[hermit.crab]

From the docs: "If you use the VRayPhysicalCamera in your scene, the parameters in this section of the Render Settings are ignored. Exception applies for the overscan, motion blur parameters: prepass samples and geometry samples, Auto Exposure and Auto White Balance."
I don't think there's a method of controlling these another way. I presume this is so as to be physically accurate.

[SonyBoy]

This seems contradictory and is implying that there are "exceptions" to those settings being ignored when using the physical camera. Meaning they should still have an effect. But that doesn't seem to be the case -- as you state there doesn't appear to be another way to adjust things like moblur (other than turning it on or off) with the physical cam.

[seandunderdale]

Is this suggesting that physical cam motion blur is correct, and there are only tools to mimic real world camera functions (shutter speed f.e) and that the motion blur settings in overrides are more subjective / non physically correct tools?

[hermit.crab]

This seems contradictory and is implying that there are "exceptions" to those settings being ignored when using the physical camera. Meaning they should still have an effect. But that doesn't seem to be the case -- as you state there doesn't appear to be another way to adjust things like moblur (other than turning it on or off) with the physical cam.

Camera overrides do not affect Physical Cameras by design. Maybe it's not as clear in the UI, hence the docs note. I'll talk to the project manager about it, though. Maybe we could add more control.

Is this suggesting that physical cam motion blur is correct, and there are only tools to mimic real world camera functions (shutter speed f.e) and that the motion blur settings in overrides are more subjective / non physically correct tools?

On second thought, it may not be a question of physical correctness, but rather a way of controlling motion blur as you would in a real-world camera.

[SonyBoy]

Camera overrides do not affect Physical Cameras by design. Maybe it's not as clear in the UI, hence the docs note. I'll talk to the project manager about it, though. Maybe we could add more control.



On second thought, it may not be a question of physical correctness, but rather a way of controlling motion blur as you would in a real-world camera.

This was precisely what my original post/question was asking. HOW can you control motion blur using the physical cam. Currently I am none the wiser since we've gone down this "guess the meaning of the docs, again" rabbit hole.

[SonyBoy]

Generally it would be better if attributes that are ignored when a physical cam is used could just be disabled/grayed out. I suppose there may be situations where a scene has both a standard Maya camera AND a Vray physical cam in use, in which case the globals would still be needed for the standard camera, but in 99.9 percent of cases you only have one render cam and it's either a physical cam or isn't.

A second choice would just be some very clear in-UI labeling of any attrs. that are Vray cam dependent. It's a bit of a confusing mess at the moment, TBH.

Or, finally, if ALL motion blur and other camera settings were camera specific and present on cameras, there would be no "global override" issues to deal with.