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paoletto / qdemviewer

Digital Elevation Model provisioner/ terrain map viewer in Qt / QML / OpenGL
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Test ASTC compression for terrarium rasters #3

Closed paoletto closed 1 month ago

paoletto commented 3 months ago

instead of converting DEM tiles into heightmaps, push them as raster textures ASTC compressed, and decode in shader. Should lead to 10x memory saving

paoletto commented 1 month ago

This seems to be a no go: apparently the ARM astc encoder seems to be unable to produce smooth block transitions. In this case that means the following, even at max quality:

image

paoletto commented 1 month ago

Update: tested the astc encoder v2 that had a deblocking option. The overall quality was however much lower, and, albeit the deblocking option seemed to have a minor positive effect when inspecting the result in a viewer, the overall result is just much poorer than the more recent version of the encoder.

Speaking of which, while inspecting the options, weighting the channels do produce an improvement. for example 2.5 0.5 0 0 to red green blue alpha produces:

image