baking GI and spherical harmonics?

[bigbossfr]

No, if you have "use camera path", you can save on one frame in "simple frame" mode with irradiance map.

But i don't knows if i can, in the same time, do this with light cache, or if must to render 2 times (first light cache, after irradiance map).

[sharktacos]

No, if you have "use camera path", you can save on one frame in "simple frame" mode with irradiance map.

Yes you can do that, and it will give you an IR map that will work for that camera (i.e. it will be view dependent). What will happen is that the info from the whole camera path will get stored in that single map. So it will work as long as you use that particular camera.

The above method that Vlado is outlining instead uses texture baking, and is view independent. That means that it can be used with any camera path. Therefore the whole idea of enabling camera path becomes moot.

The question I have (which seems very similar to the question you ask above) is whether we should also bake the LC map using this same method (so it will be view independent too), or if we need to write it for each camera using the older method (prerender)? If we have LC as the secondary GI when we bake the IR, does the secondary GI get baked into the IR map? Finally, when we then use that IR map to render, what should we set the secondary GI to?

[sharktacos]

Here's an example of the phenomenon I was describing above:
As you can see in the wireframe here the ground is a large object that covers the frame:

However the IR maps has very large gaps on the ground. Note also that there are large gaps on the right side of the barn:


Here's an illustration of the errors that this creates in the render:

[Zdravko]

If we have LC as the secondary GI when we bake the IR, does the secondary GI get baked into the IR map? Finally, when we then use that IR map to render, what should we set the secondary GI to?

Yes it does. The IR uses the LC information for its calculations. That is why you disable the secondary GI engine when rendering, just because the IR already have this information baked in it.

However the IR maps has very large gaps on the ground.

Is the ground geometry properly unwrapped? Can you attach a simple example scene?

[sharktacos]

Yes it does. The IR uses the LC information for its calculations. That is why you disable the secondary GI engine when rendering, just because the IR already have this information baked in it.


Is the ground geometry properly unwrapped? Can you attach a simple example scene?

The ground and the barn are both correctly tiled, however they are both using multi-region UV tiles (as described in the bitmap section of the vray manual). Is IR baking not compatible with multi-region UVs?

[vlado]

It works fine with multi-region UVs; for the ground, you might want to do the baking with a higher bake image resolution, so that the samples are closer together. You can use whatever secondary engine you need. There is no need to do anything with the light cache.

Best regards,
Vlado