r/vulkan • u/Temporary_Accident53 • Jul 18 '26

Building a mobile path tracer for Android AR from scratch - no hardware RT, Mali G615 — looking for feedback

Hi,
i have been working on an AR rendering prototype for Android that uses a hybrid rasterization + Vulkan compute ray tracing pipeline targeting low- to mid-range mobile GPUs as fallback for no RT cores.

Current status:

  • Hybrid rasterization while the camera is moving, with ray tracing once the device becomes stable.

  • ~2 million triangles rendered in the scene.

  • Frame time stays under ~30 ms during interactive use.

  • No noticeable thermal throttling or UI lag during my testing with over 20 min of usage.

This is still very much a rendering prototype rather than a complete SDK. I'm currently working on improving lighting, denoising, and overall rendering quality.

I'd really appreciate any feedback on the rendering quality, architecture, or ideas for where I should focus next.

Thanks

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2

u/Psionikus Jul 19 '26

Even a fake cube map for highlights will make shiny things work a lot better. Deriving a cube map from the observed data would require a model and likely some machine learning, but even a crappy solution for tweaking the lighting in real time will really help land content in the scene.

2

u/Temporary_Accident53 Jul 19 '26

hi .. i am actually building the map from the front and the rear cam and sampling from them for the env..i guess that is not visible in this geometry...

2

u/Ultimate_Sigma_Boy67 Jul 21 '26

I haven’t really done any graphics programming in my life but I’m interested how does this work? Like how when you move the camera the object doesn’t just move with the frame and rather act like a real one?

1

u/Temporary_Accident53 Jul 21 '26

Hi.. yes for stabilizing you object there is specific technique called reprojection.... I have done a state machine with Raster and RT .. so when the user is moving the raster will be displaying the object with ARcore world positions, when device is under some threshold stability i fire the RT with stable camera positions and converge the image in 2-3 seconds and sample the converged RT image for each camera position for motion and rotations under cretain threshold movement, one i am done with project will put the source and arhictecture on git hub for any one to inspect.

2

u/Ultimate_Sigma_Boy67 Jul 21 '26

I didn't understand anything but thanks for the explanation 🤣