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Erosion calculation speedup through GPGPU and future of L3DT

PostPosted: Tue Apr 23, 2019 11:07 pm
by Czorio
As erosion takes a good few hours to calculate on CPU for larger maps, a lot of time can be gained by moving this process over to the GPU.

Balázs Jákó proposes a method to just this in his paper Fast Hydraulic and Thermal Erosion on the GPU

I'll quickly highlight the more salient points in this paper:
  • "We can see that the speedup gained by utilizing GPU is very high, we reached 30 to 100 times faster execution." (4. Conclusion, final paragraph)
  • Table 1, which shows measured times
  • The paper is from 2011, meaning that the used GPU hardware (AMD HD3650 AGP and HD4870) has improved by 800% (when compared to a GTX1070) to 1100% (when compared to a RTX2070)
  • "Using GPU implementation, our algorithm can run at interactive speed even on larger terrains."

While I am not unfamiliar with the concept of "No free lunch" in software engineering, the utilization of GPGPU gets pretty close in embarassingly parallel algorithms.

With the recent news that L3DT is going freeware, I also expect that planned work on the project is winding down, and as such I would additionally suggest looking into open sourcing (parts of) the project, as L3DT has been a fairly widely used piece of software, mainly due to it's affordability when compared to other solutions, which would be greatly missed if updates stagnate. However, if I am wrong in my prediction that development is winding down, I'll happily take back these words.

I hope to hear your thoughts!