How to properly bake light cache for a DR render?

[Fredrik Averpil]

Hi,

We are doing a lot of DR rendering (it doesn't hurt to once again praise this fantastic feature by the way!) and we now have enough DR slaves that are individually calculating the light cache that I think baking the light cache prior the DR render would utilize the machines much more efficiently.

My current setup when rendering a still image using DR:
Primary engine: Irradiance map
Secondary engine: Light cache

So, I was just wondering how to bake the Light cache properly. After having conducted a series of tests it seems I should be setting the primary engine to Light cache and turning off the secondary engine (as well as "render final image"). Am I correct?


Regards,
Fredrik

[Svetlozar Draganov]

Hi,

So, I was just wondering how to bake the Light cache properly. After having conducted a series of tests it seems I should be setting the primary engine to Light cache and turning off the secondary engine (as well as "render final image"). Am I correct?
Fredrik

Yes - this is the correct workflow.

1.Set first bounce engine to Light Cache / Secondary bounce engine disabled - make sure that Auto Save option is checked and the correct path is set into Auto Save File field
2. Turn ON "Don't render final image" from Global Options
3. Click Render

For the final render stage:

1.Set first bounce engine back to Irradiance Map
2.Secondary bounce engine to Light Cache with load from file mode.
3.Turn OFF "Don't render final image"
4.Render

[Fredrik Averpil]

Hi Svetlozar,

Many thanks for confirming this!

[Fredrik Averpil]

A follup-up question on baking the light cache for still image rendering;

When baking out a Light cache map and having several renderable cameras in the scene, will each camera automatically contribute to the Light cache map being baked or am I required to bake one Light cache map per camera?

I am rendering on commandline and I am NOT specifying the camera using the "-cam" argument. My Light cache Mode is set to "Single file", which makes me believe this file is being overwritten for each camera (?), thus it is not added incrementally like with the Irradiance map.

[tashko.zashev]

When baking out a Light cache map and having several renderable cameras in the scene, will each camera automatically contribute to the Light cache map being baked or am I required to bake one Light cache map per camera?

LC is view-dependent and is generated for a particular position of the camera. Sometimes (for some specific cases) precalculated LC map could be used to render still images with different camera positions.

I am rendering on commandline and I am NOT specifying the camera using the "-cam" argument. My Light cache Mode is set to "Single file", which makes me believe this file is being overwritten for each camera (?), thus it is not added incrementally like with the Irradiance map.

You can always precalculate your GI solution (Irr map/LC) for all camera positions and then render with Irradiance map From file mode only.

[Fredrik Averpil]

Thanks Tashko,

Yes I am using the precalculated vrlmap for stills DR rendering as we often have more than one camera in an archviz scene.

I performed some tests and realized that the light cache vrlmap is overwritten (rather than added to) so I bake out a vrlmap for each renderlayer/camera. All good!

[sharktacos]

Yes - this is the correct workflow.

1.Set first bounce engine to Light Cache / Secondary bounce engine disabled

I thought that this should be set to LC/LC. In the Rendering a walkthrough tutorial for Max is says to do this (Part I:1.4. "In the Render scene dialog, turn Global illumination on and set both the Primary GI engine and the Secondary GI engine to Light cache." So is there a reason that this would not also be the case with Maya?

thx

[tashko.zashev]

Hi,

I thought that this should be set to LC/LC. In the Rendering a walkthrough tutorial for Max is says to do this (Part I:1.4. "In the Render scene dialog, turn Global illumination on and set both the Primary GI engine and the Secondary GI engine to Light cache." So is there a reason that this would not also be the case with Maya?

thx

Both methods should work.