# Can raytracing be used to determine a certain gas distribution in a real planet's atmosphere?

I want to calculate the capacity that the planet Mars has regarding protecting against UV-light for a final project I will be doing my last year in upper secondary school. UV-light is mainly absorbed in the atmosphere by ozone gas particles and I'm wondering whether it is possible to simulate the ozone gas distribution on Mars and calculate its atmosphere's capacity to absorb the UV-light?

• Are you looking to create a visualization or to show the results of the physics/math? If it is the physics portion then this probably isn't the best forum. I would recommend moving this to one of the physics sites for that. If you are looking to create a visualization then could you please expand on your question giving us more detail about the expected output. Commented Aug 19, 2023 at 15:14

I think it is possible via differentiable rendering techniques, but you are going to need some data for it. Like when you have your model, for example, a spherical heterogeneous scattering medium represented by density grids, and to optimize the parameters you will need observation since this is going to be underdeterminated.

I am merely stating a possibility here. Note that to get things right, there are some other things you should know:

• Make sure geometric optics can handle your task since current theory based on wave-optics is not so mature. This is very task-specific, some might require the recently put forward ideas like wave-optics rendering, others might involve polarization related rendering.
• Try to get a correct mathematical model, for example, the scattering medium is very likely to be non-exponential. For non-exponential medium, you can refer to:

[1] Bitterli, Benedikt, et al. "A radiative transfer framework for non-exponential media." (2018).

[2] Jarabo, Adrian, Carlos Aliaga, and Diego Gutierrez. "A radiative transfer framework for spatially-correlated materials." ACM Transactions on Graphics (TOG) 37.4 (2018): 1-13.

[3] Vicini, Delio, Wenzel Jakob, and Anton Kaplanyan. "A non-exponential transmittance model for volumetric scene representations." ACM Transactions on Graphics (TOG) 40.4 (2021): 1-16.

These works are one of the earliest works that introduce non-exponential medium formally into the field of rendering. They are easier to understand compared to the follow up works (especially the first one). The third one has already put the non-exponential model into the inverse rendering problem. So, if exponential model is not enough (wow, here comes pain), finding a good rendering framework and do refactoring work can be, yeah, fun.

• To model the surface reflected radiance accurately, you will need a good PBR-BRDF for Mars.
• Read more literature on this topic, being the first one to do something always means pain...
• Like how differentiable renderer can be used in estimating the density of scattering medium
• How to efficiently render heterogeneous medium

Surely these are the problems you are going to solve, and I hope this would help you.