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beersandrew / usd-thumbnail-generator

Given a USD file, take a picture and assign it as it's thumbnail.
Creative Commons Zero v1.0 Universal
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Default image extension #16

Open beersandrew opened 1 year ago

beersandrew commented 1 year ago

Nick Porcino mentioned about having a default file format of exr since he can color manage exr and not png.

@hybridherbst wanted to discuss.

creating this issue for a discussion about the pros and cons of different default extensions

meshula commented 1 year ago

jpeg, png, and exr are built into UsdImaging and always available to Hydra as of 23.11. As of 23.08 OpenEXR is only available via the OIIO plugin. EXR is always available to usdz, as of 23.08.

8 bit imagery saves space. exr is the HDR format of choice.

jpeg

lossy good compression srgb, 8 bit no alpha channel

png

lossless moderate compression (LZ77) linear or srgb, 8 or 16 bits alpha channel (un-premultiplied)

exr

lossless moderate compression (LZ77, dwa a and b) linear, 16 or 32 bits color space specified as chromaticities plus white point alpha (un-premultiplied) rich attribute system including camera matrices, SMPTE 2065 attributes, and camdkit

exr features not yet exposed to usd, but expected in the future

depth (z) images deep pixels (multiple samples per pixel, depth information) unlimited layers (diffuse, specular, etc) unlimited parts (frame 0, frame 1, etc)