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[main] Downsample transcripts for quadtree tiling construction - #83

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Tobiaspk:feature/downsample-transcripts-quadtree
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[main] Downsample transcripts for quadtree tiling construction#83
Tobiaspk wants to merge 3 commits into
dpeerlab:mainfrom
Tobiaspk:feature/downsample-transcripts-quadtree

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@Tobiaspk

@Tobiaspk Tobiaspk commented Aug 28, 2026

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Closes #77: adds an optional max_transcripts parameter (default 50M) that builds the training-tile quadtree on a random subsample once the point count exceeds it, scaling max_size by the same fraction so leaf density still approximates the full-dataset tree.

This limits GPU memory and avoids cuSpatial's numeric overflow issues (especially in atera), and improving quadtree tiling stability. it does not improve construction time, since the bottleneck is computing global bounds/scale over all points.

Subsamples points before building the training-tile quadtree once the
count exceeds max_transcripts (default 50M), scaling max_size and its
retry step by the same fraction. Bounds/scale/max_depth still use the
full point set, so leaf boundaries stay comparable to the full-dataset
tree.
@Tobiaspk Tobiaspk changed the title Downsample transcripts for quadtree tiling construction [main] Downsample transcripts for quadtree tiling construction Aug 28, 2026
@Tobiaspk

Tobiaspk commented Aug 28, 2026

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Almost Identical tiling results as compared to the full 1B quadtree tiling tree.

image

Performance not improved, but this avoids numeric overflows:

image

@Tobiaspk

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Defaults max_transcripts to 50 Mio.

…h construction

The tiling_max_transcripts CLI default (50M) only reached
QuadTreeTiling; points_in_polygons/get_quadtree_index calls made
during prediction-graph construction never received it, so quadtree
overflows (issue dpeerlab#77) weren't guarded on that path.
max_transcripts read as a hard cap on transcripts; the parameter only
downsamples points fed into quadtree construction, so the old name was
misleading throughout the CLI, ISTDataModule, and geometry/tiling call chain.
@Tobiaspk

Tobiaspk commented Sep 3, 2026

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Will probably deprecate this in favor of the upcoming cuspa package. Not yet working anyway

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Downsample transcripts (max_transcripts) when building the tiling quadtree to bound memory / avoid overflow

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