Renderer FAQ
Troubleshooting
Q: I see a lot of ugly color banding, is this a bug? How to fix?
A: You have linear lighting enabled with high-precision rendering disabled, reapply your preferred graphics preset to fix it.
Hardware Compatibility
Q: Do you have a plan for Vulkan?
A: Yes, a Vulkan renderer is in development.
Q: Will you provide a renderer free of support from very old hardware?
A: Yes, the Vulkan renderer is meant to drop support for very old hardware.
Q: Does the OpenGL rendered have old hardware compatibility?
A: Yes, it supports down to OpenGL 2.
Q: Does the old-OpenGL compatibility mode slow down the renderer on newer hardware?
A: No, the old-OpenGL or new-OpenGL execution path is selected at map load.
Q: Do you will keep the old hardware compatibility in OpenGL renderer?
A: Yes, since the Vulkan renderer drops support of very old hardware, we don't have to drop that support in OpenGL.
Map compatibility
Q: Do you care about compatibility with legacy maps?
A: Yes, we consider legacy maps from the id Tech 3 generation (Quake 3, Tremulous, Wolf: ET…) should be supported and rendered the way they were.
Q: Is the compatibility with legacy maps considered complete?
A: Yes, except the alphaGen lightingSpecular feature (see below), everything should now be supported.
Q: Do you promise to be compatible with every experimental pre-released unfinished concept map that may be found in leaked dumps or attics?
A: No, if it works, good for you; if it's easy to make it work, we may have a look; if you propose a patch, we may accept it.
Lighting
Q: Did you change the way the map lighting was rendered?
A: No, but we added a new way to process lighting (linear lighting, aka sRGB support).
Q: Does the linear lighting (sRGB support) change the way existing maps are rendered?
A: No, maps have to be explicitly rebuilt for the linear lighting for the engine to use linear lighting.
Q: Can a legacy map be mistakenly rendered with the linear lighting?
A: No, maps have to be explicitly rebuilt for the linear lighting for the engine to use linear lighting.
Q: Does rebuilding a map with linear lighting change the way maps are rendered?
A: Yes, that's the purpose, the equations were not physically correct before.
Q: Is it still possible to rebuild maps the old way?
A: Yes, we provide multiple old map build presets. The renderer keeps the support for what is built the old way.
Q: Did the overbright patches change the way legacy maps are rendered?
A: No, they restored the way legacy maps were rendered. Previously we had a bug, so if you see a change, it's because a bug was misrendering something before.
Q: Did you have to rollback the overbright support?
A: No, our first fix was incomplete when we released it first, we then shipped an additional fix to finish the compatibility support. It's incremental improvement.
Q: Do you have tone mapping?
A: Yes.
Q: Are the linear lighting and tone mapping meant to work together?
A: Yes, they even work better together.
Q: Will you provide adaptive lighting?
A: Adaptive lighting work is planned, it is in progress but not merged yet.
Q: Are the linear lighting (sRGB support) and adaptive lighting meant to work together?
A: Yes, in fact, both linear lighting, tone mapping and adaptive lighting are not only meant to work together, they are cumulative. Adaptive lighting requires tone mapping to work and requires linear lighting to be correct.
Features
Q: Do you support vertex lighting?
A: Yes.
Q: Do you support grid lighting?
A: Yes.
Q: Do you support light mapping?
A: Yes.
Q: Do you support deluxe mapping?
A: Yes.
Q: Do you support grid deluxe mapping?
A: Yes.
Q: Do you support external lightmaps?
A: Yes.
Q: Do you support mixed vertex lighting and light mapping on world surfaces?
A: Yes.
Q: Do you support terrain blending?
A: Yes, including with multitextured materials.
Q: Do you support portals and mirrors?
A: Yes.
Q: Do you support recursive portals and mirrors?
A: Yes.
Q: Do you support portal alpha blending?
A: Yes
Q: Do you support distance-based alpha blending?
A: Yes.
Q: Do you support heat Haze materials?
A: Yes.
Q: Do you support water materials?
A: No, the code is there but broken, we haven't fixed it yet.
Q: Do you support specular mapping?
A: Yes.
Q: Do you support normal mapping?
A: Yes.
Q: Do you support height mapping?
A: Yes.
Q: Do you support PBR?
A: Mostly, but it still work in progress.
Q: Do you support cube mapping?
A: Mostly, but it still work in progress.
Q: Do you support videoMap?
A: Yes.
Q: Do you support the RoQ video format?
A: Yes.
Q: Do you support a more modern video format?
A: Not yet.
Q: Do you support alphaGen lightingSpecular?
A: Not yet: Formats/Known regressions since Tremulous
Q: Do you know any other renderer regression since Tremulous?
A: No. If you find one, please report: issue tracker
