Fix tangent/bitagent encoding when computing vertex skinning#120901
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Gaktan wants to merge 1 commit into
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Fix tangent/bitagent encoding when computing vertex skinning#120901Gaktan wants to merge 1 commit into
Gaktan wants to merge 1 commit into
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What problem(s) does this PR solve?
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My previous PR #117401 had some caveats. For instance, it did not take the binormal sign encoding into account.
The way it works is that the binormal sign is encoded in Oct.y. Oct.y is encoded as UNORM16, so values > 0.5 means positive, and values < 0.5 means negative. Since UNORM16 encoding does not allow a value of exactly 0.5 (aka zero once unpacked), the binormal sign was flip-flopping between positive and negative.
The fix is to clamp the Oct.Y value between [1.0/65535.0; 1-(1.0/65535.0)]. This also avoids the issue with compression detection altogether (what PR #117401 tried to fix).
I also removed usage of some
signfunction as its not very efficient on the GPU because it handles many different cases (+/-INF and zero). It's a lot simpler to just check if >= 0