Is it possible to recover illumination.

[EMwavelength]

Hi,
Is it possible to recover unknown illumination observed in an image,i.e a diffuse object lit by sunlight? I know it's a big problem in graphics to recover unknown illumination, for inverse rendering illumination must be known, is mitsuba able to solve such problem?

[Speierers]

Yes it is be possible.

Mitsuba 3 is able to produce gradients for the parameters of emitters (e.g. area light, point light, envmap, ...). It is therefore possible to write a simple optimization pipeline that optimizes for the texture data of an environment light for instance.

[EMwavelength]

Hi,
I tried your suggestion, but it seems the optimizer is unable to recover direct sunlight, don't know whats causing it, please guide me in right direction.

Target:

Optimized:

TargetEnvmap:

OptimizedEnvmap:

[EMwavelength]

Hi,
Thank you for the answer your suggestions works to some good degree after i run optimization a little bit more.
Optimizationcorrected:

TargetOverExposed: