search

sapo17 / BachelorThesis

Simple material parameter estimator tool using Mitsuba 3 and Dr.Jit.
2 stars 0 forks source link

Optimize images from provided material properties #27

Closed sapo17 closed 1 year ago

sapo17 commented 1 year ago

Email from David:

We were wondering if it is possible to find (guess?) homogeneous material parameters that match the appearance. Specifically the parameters highlighted in the attached images (one is from our own software, the other from Blender): roughness, transmission, index of refraction, and base colour. (I think Blender combines “roughness” and “transmission roughness”, we don’t make that distinction at the moment in our software.) In this case, we’re basically just looking for ~6 numbers (3 for the colour) – so that could maybe be done by trial-and-error. (I’m hoping Mitsuba3 supports a similar material definition, maybe they implement GGX directly too.) david_material1_151122 david_material2_151122

sapo17 commented 1 year ago

Added support for alpha parameter #2

sapo17 commented 1 year ago

Email from David:

I think what you’re looking for in the Mitsuba materials is the Rough dielectric with distribution GGX, and mostly focusing on the parameters alpha and eta (and base colour obviously).

As I understand the base colour basically defines how much light the material absorbs (so a dark colour gives a highly absorptive material), whatever light is not absorbed must be either reflected or transmitted. The ratio between reflection and transmission – I think – results from the relative IOR. And roughness just makes it look diffuse/blurry as opposed to shiny/clear.

sapo17 commented 1 year ago

See commit

Support for optimizing more scene parameters will be defined #30