Support equirectangular coordinate output for cmgen about filament HOT 5 CLOSED

Fixed in #317

from filament.

That's a good idea. It wouldn't be difficult to add such support I believe.

from filament.

Another very useful format are octahedral maps as discussed in chapter 16 of WebGL Insights. The main advantage of octahedral maps is the lack of seams and distortion.

By using this technique we can work around the following WebGL issues as mentioned in this ticket that still stand as of today in my experience:

• textureCubeLod is still not supported in Firefox on OSX
• seamless cubemap filtering is not available in WebGL 1
• most importantly we can't render to HDR CubeMap mipmap levels > 0 on iOS

One implementation is mentioned in this thread.

The excellent paper that is referenced in the thread is the following (the link in the thread is dead):
https://pdfs.semanticscholar.org/fcb9/a6dbdf7b4c31f94e481cf101c83b73ea6410.pdf

A tooling implementation of octahedral maps can be found in CMFT.

I understand that WebGL is not a supported target of Filament but having it as an option would be very beneficial.

from filament.

WebGL is a target now but WebGL 2 which follows OpenGLES 3.0 which means it provides seamless cubemap sampling. We are not planning on supporting WebGL 1 at this point. Note however that cmgen contains code to generate cubemaps with seam fixups built-in. It's not as good as octahedral maps but it helps. That said I'd be more than happy to accept contributions to support octahedral maps. We just can't really justify doing it ourselves at this time :/

from filament.

Thank you!

from filament.