Optimizing w.r.t. Environment Light Rotation?

[AnsonSavage]

Howdy!

Using mi.traverse(scene) to inspect the parameters of my scene, I found that the to_world matrix of my environment light isn't differentiable:

environment_light.sampling_weight                                float             EnvironmentMapEmitter  
environment_light.scale                                 ∂        Float             EnvironmentMapEmitter  
environment_light.data                                  ∂, D     TensorXf          EnvironmentMapEmitter  
environment_light.to_world                                       Transform4f       EnvironmentMapEmitter  

I would love to optimize with respect to the rotation of the environment light. Is there any way to do this?

Thanks!
Anson

[miangoleh]

you can optimize "to_world.matrix" (look at #151 ). However it might cause issues as it won't make sure its a valid transformation. The better way would be to define latent variables and then use them to update the to_world parameters.