How to configurate ray-tracing sovler in AODT?

Accelerated Computing Aerial Forum
1

Hello,

Is it possible to configure the parameters of the ray-tracing solver in AODT, similar to how we can edit config_ran.json inside the aodt_sim container?

I found some relevant parameters in the Sionna RT API (Ray Tracing — Sionna 0.18.0 documentation), such as the number of reflections, diffractions, and scatterings for the ray-tracing solver.

Currently, on the AODT UI, I can only edit parameters like the number of emitted rays, scene interactions per ray, maximum number of shown paths per RU-UE pair, and ray sparsity.

If these specific settings are not configurable within AODT, is it possible to modify the source code and rebuild the aodt_sim container? So far, I’ve found the calculate_rays() function in ch_utils.py located at aodt_bundle/backend_bundle/aodt_sim/src_be/components/chanemu/. However, it seems to only calculate reflection paths.

Could you provide any guidance on how to trace and adjust the ray-tracing solver settings in AODT?

Thank you for your help.

Best regards,
JunXian

2

I found some additional information in the AODT documentation (Additional Information - NVIDIA Docs).

Within the code, I located aerial_emsolver_api.h at aodt_bundle/backend_bundle/aodt_sim/external/aerial_emsolver_api/api/. However, the ray-tracing configuration only includes settings such as:

struct RTConfig {
    int num_rays_in_thousands{};
    int max_num_bounces{};
    bool use_only_first_antenna_pair{};
    bool calc_tau_mins{};
    bool simulate_ran{};
}

I couldn’t find any options for adjusting the number of reflections, diffractions, or scatterings for the ray-tracing solver.

Additionally, I found interaction type definitions in the code:

enum EM_INTERACT_TYPE : unsigned int {
    Emission = 0,
    Reflection = 1,
    Diffraction = 2,
    Diffuse = 3,
    Reception = 4,
    Reserved,
}

Does the current ray-tracing solver in AODT simulate transmission or diffraction effects? These interactions seem critical for accurate modeling, particularly in indoor environments where this phenomenon have a significant impact.
Thak you.

3

@junxian The AODT does model diffraction. While the the number of interactions are parameterized, it is not possible to configure the individual interactions. The source code for EM solver is not publicly available. The nature of interaction (reflection/diffraction etc…) is recorded in the databases.

4

@kpasad1 Thank you. I understand that it may not be possible to set individual parameters for specific interactions, but is there an option to specify the maximum number of reflections or diffractions globally within a scene?
Additionally, does the EM solver account for attenuation effects due to obstacles such as walls, windows, or other materials?

5

@junxian The parameter “# scene interactions per ray” specifies the maximum number of interactions for every ray. The same parameter is applied for the entire scene. We cannot specify, e.g., the number of refection that a ray can go through, or the number of diffraction it can go through. We can only specify the total number of interactions.
In our current release, attenuation effects are not modeled, though we may add such effects in the future.

6

@kpasad1 Thank you for your prompt reply. It is clear to me now.

7

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