Spray brush mode: bakes a procedural scattered-dot mask per stamp (random
position, size, alpha within the brush disc) and paints it through the
existing single-stamp pipeline; dot centers clamped to (0.5 - dotR) so the
spray footprint matches the solid brush radius.
Paint interval: float on MeshPainter; 0 keeps the continuous interpolated
stroke, >0 emits a single timed dab every x.xx seconds.
Color picker alpha: horizontal alpha bar on both HSV pickers, runtime-built
in Rebind (no prefab re-bake), passed through to brushColor.a / emissionColor.a.
Metallic/smoothness + occlusion paint opacity: new opacity fields applied in
both CPU and GPU backends (GPU MSO draw split into MS and occlusion sub-stamps
for independent opacity), with cloned alpha sliders wired into the HUD.
Also includes the prefab layout tweaks and scene adjustments.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>