meleki/chameleon
1
0 Fork 0
Code Activity

MeshPainter: Kugel-Brush statt Box, cornerGuard entfernt

Browse Source 
Stamp testet den Brush wieder als 3D-Kugel (du²+dv²+dn² = r²) statt
als Box (|du|,|dv|,|dn| = r) — konsistent über CPU, GPU-Brush und
Preview. Die Box reichte diagonal bis r·√3 und spannte einen 2r-dicken
Slab entlang der Normale, wodurch an Nähten/Kanten/dünner Geometrie auf
die Gegenseite/Nachbarinseln gemalt wurde. Die Kugel reicht in jede
Richtung exakt r und überbrückt echte 3D-Nähte weiterhin, greift aber
nicht mehr über r hinaus.

cornerGuard war nur ein Pflaster gegen genau diesen Box-Übergriff und
ist damit überflüssig: Config-Felder, Suppress-Check und Helper
(DabWrapsAroundCorner, CornerWrapFraction, InBrushBox, SquareReach)
entfernt.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
This commit is contained in:
adminandClaude Opus 4.8 committed 2026-07-14 22:11:41 +02:00
1 parent 2195427e6c
commit 1f42c990fb
5 files changed
+27 -131
Download Patch File Download Diff File Expand all files Collapse all files

No files matched your search

Assets/Shaders/MeshPaintBrush.shader
+7 -8
View File
@@ -5,8 +5,9 @@
// passed through to the fragment shader. There, per texel, the offset to the brush
// center (_BrushCenter, in local mesh space) is projected onto the stamp's tangent
// frame: _BrushU (right), _BrushV (up) and _BrushNormal. The texel is painted only
// if it lies inside the box (|du|,|dv|,|dn| <= _BrushRadius); the brush mask
// (_MaskTex, sampled along du/dv) then provides the per-texel OPACITY:
// if it lies inside the brush SPHERE (du²+dv²+dn² <= _BrushRadius²) - isotropic reach
// like the original circle brush, so the dab never bleeds across a seam / around a
// corner. The mask (_MaskTex, sampled along du/dv) then provides the per-texel OPACITY:
// opacity = luma(mask.rgb) * mask.a * _BrushColor.a
// and the color is alpha-blended over the existing paint (source-over). So a mask
// gray value of 0.5 paints at 50%, white = full, black/transparent = nothing.
@@ -86,13 +87,11 @@ Shader "Hidden/MeshPaintBrush"
float dv = dot(d, _BrushV);
float dn = dot(d, _BrushNormal);
// Square stamp in the tangent plane + depth bound (keeps the seam-
// bridging 3D behavior while preventing bleed to far surfaces).
clip(_BrushRadius - abs(du));
clip(_BrushRadius - abs(dv));
clip(_BrushRadius - abs(dn));
// Brush sphere: isotropic reach r in every direction, so the dab bridges seams
// (both sides of a 3D edge) yet never bleeds onto far/adjacent surfaces past r.
clip(_BrushRadius * _BrushRadius - (du * du + dv * dv + dn * dn));
// Mask -> opacity. du/dv in [-r,r] -> uv in [0,1].
// Mask -> opacity. The sphere guarantees |du|,|dv| <= r -> uv in [0,1].
float2 muv = float2(du, dv) / _BrushRadius * 0.5 + 0.5;
fixed4 m = tex2D(_MaskTex, muv);
float luma = dot(m.rgb, fixed3(0.299, 0.587, 0.114));
Assets/Shaders/MeshPaintPreview.shader
+3 -5
View File
@@ -2,7 +2,7 @@
// WITHOUT painting. Two modes, selected via _PreviewMode:
//
// 0 = On-surface: the baked mesh is drawn again (object transform) and each
// fragment runs the SAME box + mask test as the paint shader, in local mesh
// fragment runs the SAME sphere + mask test as the paint shader, in local mesh
// space (_BrushCenter/_BrushU/_BrushV/_BrushNormal/_BrushRadius). So the
// preview wraps over curvature and across UV seams exactly like the paint
// would land. Depth test (LEqual) + a slight polygon offset keep it glued to
@@ -74,14 +74,12 @@ Shader "Hidden/MeshPaintPreview"
float2 muv;
if (_PreviewMode < 0.5)
{
// On-surface: same square box test as the paint shader, in local space.
// On-surface: same brush-sphere test as the paint shader, in local space.
float3 d = i.local - _BrushCenter;
float du = dot(d, _BrushU);
float dv = dot(d, _BrushV);
float dn = dot(d, _BrushNormal);
clip(_BrushRadius - abs(du));
clip(_BrushRadius - abs(dv));
clip(_BrushRadius - abs(dn));
clip(_BrushRadius * _BrushRadius - (du * du + dv * dv + dn * dn));
muv = float2(du, dv) / _BrushRadius * 0.5 + 0.5;
}
else