[custom DR solutions only] New parameter needed for network rendering!
Note: this guide applies only if custom render farm solutions based on weighted merging multiple images are used - for example in case of using the Corona Image Editor (not with disjunctive region stitching, like in backburner).
This behavior was also present in versions of Corona Renderer older than 1.7.
We have received multiple reports about "bad anti-aliasing when rendering on farm".
The issue is caused by Corona not doing AA on first pass. This is done for 2 reasons:
1) It increases the quality of first preview user sees significantly
2) It is a integral part of how rendering additional render elements without AA works
This is not a problem when rendering an image with, for example, 100 passes locally. But if distributed rendering is done on 50 machines, each rendering just 2 passes, it means that 50 passes with AA and 50 passes without AA will be merged, causing bad AA.
Corona's native distributed rendering and Corona's "resume rendering" feature (in version 1.7+) handle this automatically. When a custom distributed rendering solution is used, to get best results, either avoid each computer rendering just few passes, or use the string option listed below (works only in Corona 1.7+).
- Avoid each computer rendering just a few passes. 50 computers rendering just 2 passes each is wrong. 2 computers rendering 50 passes each is good.
Use the following string option on all but one machine:
bool shading.firstPassWithoutAa = false
Note that the machines with this option will not render elements without anti-aliasing, and will output black frames for these elements instead. Merging images when single machine did not have this option should work fine even for such elements.
The newest version of Corona Renderer can be downloaded from https://corona-renderer.com/download/