When using maya cameras “cameraShape.postScale” over 1 and then combining it with maya image planes offsets (imagePlaneShape.offsetX/imagePlaneShape.offsetY) the result differs between maya viewport and vray VFB render.
I am unsure if this is a bug or a difference of render settings vs viewport settings - maybe i am missing something but i cannot get the combination to work in vray
Would be great to find a workaround or a way to fix this…unfortunately we cannot use 2d pan zoom
It seems the Pre/Post Scale parameter is not previewed in the viewport. Logged as internal tracker ID: VMAYA-13751. The render appears correct, though. Unsure if there’s a workaround.
hm, so it would be the maya viewport that is wrong?
It feels like one or the other applies the offsets in a different order-or it could be a different image center that is used?
if i disable the offsets entirely on the image plane the VFB render matches the “original” viewport framing but then obviously the maya viewport is wrong. oh well…
Actually, you may be right. I jumped to conclusions too fast. It actually works in the viewport - if you add an object and manipulate the post/pre scale, it will zoom in/out correctly both in the viewport and render. It has something to do with the image plane itself and how it is projected from the camera, because if you view it from a persp view, both offset and post/prescale preview correctly. I’ll investigate further.
EDIT: Arnold seems to maintain the offset result from the viewport, so it’s probably a V-Ray thing (and it very well may be a different image center/order thing). I’ll edit the report to match the new findings. Thanks for the feedback.
Just noticed something similar and maybe related.
When using Overrides Overscan mode to add pixels AND using 2d pan zoom OR custom Film Offset and Post scale the resulting framing is completely off, shifted buttom right in my case.
My guess is : the overscan caluclation by vray is not considering the possibility of active Post Scale and Film Offsets.
This is for our case extremely annoying. We cannot anymore rely on vrays Overscan mode for shots that have these post scales and offsets.
Getting more and more frustrated by these framing problems. I have not found a clean solution.
Thanks fro the report. Indeed, the issue seems to be similar and probably stems from the same thing as the previously reported one. I’ve logged the overscan issue as VMAYA-13809 and will notify the product owner to assign somebody to have a look at what exactly is happening behind the scenes.
Thanks fo the reply.
What would really help me right now: is thre a way to compensate mathematically the vray behavior to match again what is intended/needed
I managed to eyeball it but it doesnt make any sense to me and probaply is only a shot based fix, not a global workaround.
Doesn’t seem like there’s a simple formula - I tried matching a Pre/Post Scale = 2 result with an Overscan of 100. To make it right in the middle (as with pre/post scale = 1), I had to add a film offset of 0.061 / -0.054. The way I did it, which you may use instead of eyeballing, is to save a post/pre scale = 1 image in the history, set it to compare with what’s rendered by the IPR, and start adjusting the offset value. This is quite tedious, though. Better we fix the issue.
did the same thing, unfortunately if there is animation on the attributes this wont work.otherwise a simple multiplier as override would have been a solution
Right now i am changing our setup to change the resolution in maya native and use pre scale value to compensate.
