Previous post:
https://forum.corona-renderer.com/index.php?topic=27617.0I am making this post in relation to a previous feature request that I made and found a work around for.
The bases of the request was to use an object in the scene as a render region using a gbuffer ID. The work around uses an object with a material set as transparent so in theory it should just render everything within it’s form. Great for patch rendering animated scenes with cameras and objects moving.
So I did some more testing and have an issue as the render behaves differently when rendering selected ID is set. The render takes long time and renders to a much lower than expected noise threshold.
All attached renders are set to 40 passes, and I would expect it to reach around 2-3% noise. The first render has render selected by Gbuffer ID and the ONLY difference in the second render is that I drew a region tight in around the rendered area. The third render is EXACTLY the same except the region covers the whole frame.
First Render (no region selected ID only)
render time -26 minutes
noise level - 0.96%
Second Render (with tight region)
render time -7 minutes
noise level - 2.63%
Third Render (with full frame region)
render time -26 minutes
noise level - 0.96%
The second image is how I would of expected the first image to also render. In fact I would of expected all 3 to render the same!
Although there is a time saving in set up time it leaves relatively little point in using gbuffer instead of rendering many regions.
I would expect a whole frame to render in about 45 minutes. We have had similar experiences with render time in the past using Obj ID (never been trying it with a transparent object before) but never really investigated it any further other than rendering to a noise threshold which for animation we found flickery.
Why would a region bigger that the object effect the render so much and Is this an expected behaviour? Has anyone else experience similar? and most importantly is there a solution (other than regions)
Thanks for your time.
