VRay Physical Camera Question

V-Ray V-Ray for 3ds Max General
1

If I have precalculated my IR map and Lightcache with a VRay phys cam do I have to use the same settings when I render the final images?

The reason I’m asking is I’ve used a camera with a shutter of 1/30 for the calc phase by mistake. When I use this cam for the final renders there is too much motion blur. So I want to know if it is ok to change the shutter speed and the ISO to compensate?

Sorry would test this myself but someone else has the file open atm and we need to render over the weekend - deadline looms…

Thanks Dan

2

Not sure about the Motion Blur part but I have re-rendered a scene using different shutter speed & ISO values from a pre-saved IRR map & it was fine [although there was no Motion Blur in the image.]

3

Thanks for the reply. I tried it over the weekend and you are right, you can change the camera settings.

Dan

4

I think vlado mentioned it’s fine once the camera used to calc the irmap and lcmap didn’t have animated iso / f stop.

5

I guess animating the ISO or shutter would be the same as animating the intesity of a light - you would need an IR map per frame.

All I wanted to do was double my ISO and shutter speed without re-calculating the IR and lightcache.

6

As long as the aforementioned issues were taken into account,[joconnell I think vlado mentioned it’s fine once the camera used to calc the irmap and lcmap didn’t have animated iso / f stop. ] you wouldn’t need a IR map per frame as the Camera is simply adjusting how bright the IR map gets rendered at.
Think of being inside a building and then going outside & adjusting the iso/shutter speed lower to deal with the extra light. The irradiance map would stay the same and the camera would adjust how much light to render with

Cheers