Bidirectional - World Background reflections problems

Component:YafaRay Core
Category:bug report
Assigned:David Bluecame


As reported by surena in when using Bidirectional with World Background there are problems.

Based on what surena reported, I did several tests and found these issues:

* When using single color/texture background, the background color/image does not show in the specular/glossy reflections at all.

* When using sky background, YafaRay crashes.



I've tried old YafaRay versions and same happens. So, this problem seems to have been happening for a long time. I will investigate.

bidir-bg-issues.blend483.58 KB
bidir-bg-issues.jpg29.5 KB



Title:Bidirectional - World Background problems» Bidirectional - World Background reflections problems
Category:bug report» feature request
Priority:critical» normal
Status:active» postponed

While investigating, I don't yet understand how the Bidirectional works, but it looks like it was not originally designed to show the background in the reflections at all.

So, I will change this to a Feature Request, as it would require fundamental changes in the Bidir integrator, and I will postpone it as it's not a priority now.

This integrator is very buggy and I'm very often tempted to remove it from YafaRay-E altogether. For now I will leave it, but I will not try to "fix" now something that looks like was never implemented in the first place.


Status:postponed» closed

The Bidirectional integrator has been declared Deprecated so it will not receive further attention, fixes or updates. See:

Therefore, closing...


Version:» <none>
Component:Code» YafaRay Core
Status:closed» active

We will again try to improve Bidirectional, so reopening...


Category:feature request» bug report



That's actually a very interesting suggestion. Moreover the link points to a repository with MIT license that I think is compatible with YafaRay.

I'm considering rewriting the Bidir. I was thinking first about using Metropolis Light Transport, but now this looks interesting.

The biggest problem I have here is that YafaRay material code is... exotic to say something. There are many material-specific variables in the integrators and for example one of the biggest problems with the current Bidir is that the integrator is not using the material variables the same way as the others. It's really difficult to find if the problems are caused by a bad design, some implementation error or just because it's incomplete and/or partially incompatible with YafaRay's current material system.

If I try to implement any other integrator I will encounter similar problems. Therefore I need first to learn and understand very well how the current integrators and materials work and "interlock" before I can try any improvements to them.

In any case I will keep this in mind, good suggestion, thanks!!


Well, I think it's better to have first the PBR shading system.


Just Surena,

also we think that now the next step is the implementation of the PBR that will surely make YafaRay most complete and up to date!!

Hello everybody