STAGE_AO flags a two-sided depth spike (the smaller one-sided step two pixels out, capped by the
second difference: ~0 on planes, grazing planes, silhouettes and contact creases) and stores the
smoothness in alpha. STAGE_BLUR turns the spike density of its 4x4 window into a foliage mask,
widens the depth tolerance there (up to 11x) and scales the occlusion by 1 - 0.4 * mask. Smooth
windows are unchanged. WOW_AO_DEBUG=5 shows the mask. LIGHTING.md documents this and the two
earlier followups fixes.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
