realtime rendering v3 page 351
Moire pattern
sruface acne
artifacts
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用 setstate
dx
depthslopescalebias
depthbias
gl
setPolygonOffset(depthslopescalebias,depthbias,clamp)
depthslopescalebias
depthbias经验值，。。。。。wip
/// The offset is computed by multiplying the maximum depth slope of
/// the primitive [sqrt((dz/dx)^2 + (dz/dy)^2)] by _factor_, adding in
/// the minimum resolvable difference in depth values multiplied by
/// _units_, and clamping the result as described in the documentation
/// for _clamp_.
/// \param factor Value multiplied by the maximum depth slope when
/// computing offset.
///
/// \param units Value multiplied by the minimum resolvable depth
/// difference when computing offset.
///
/// \param clamp Value used to clamp the computed offset.
/// If `clamp` is positive, the computed depth offset will be clamped
/// to a value less than or equal to `clamp`. If `clamp` is negative,
/// the computed depth offset will be clamped to a value greater than
/// or equal to `clamp`. If `clamp` is zero, the computed depth offset
/// will not be clamped.
void SetPolygonOffsetClamp(float factor,
float units,
float clamp);