升级6.4.升级水，升级天气

Packages/com.waveharmonic.crest/Runtime/Shaders/Surface/Geometry.hlsl

@@ -11,9 +11,7 @@
 // These are per cascade, set per chunk instance.
 CBUFFER_START(CrestChunkGeometryData)
 float _Crest_ChunkMeshScaleAlpha;
-float _Crest_ChunkMeshScaleAlphaSource;
 float _Crest_ChunkGeometryGridWidth;
-float _Crest_ChunkGeometryGridWidthSource;
 CBUFFER_END
 
 m_CrestNameSpace
@@ -93,6 +91,22 @@ void SnapAndTransitionVertLayout(in const float i_meshScaleAlpha, in const Casca
     SnapAndTransitionVertLayout(UNITY_MATRIX_M, i_meshScaleAlpha, i_cascadeData0, i_geometryGridSize, io_worldPos, o_lodAlpha);
 }
 
+// Fix precision errors at edges.
+void PatchVerticeLayout(const float2 i_ObjectPosition, const float2 i_CameraPosition, inout float2 io_PositionWS)
+{
+    // Scale up by small "epsilon" to solve numerical issues. Expand slightly about tile center.
+    // :WaterGridPrecisionErrors
+    const float2 center = i_ObjectPosition;
+    const float2 camera = abs(i_CameraPosition);
+    // Scale "epsilon" by distance from zero. Gaps look bad from above surface, and
+    // overlaps look bad from below surface. We want to close gaps without introducing
+    // overlaps. A fixed "epsilon" will either not solve gaps at large distances or
+    // introduce too many overlaps at small distances. Even with scaling, there are
+    // still unsolvable overlaps underwater (especially at large distances). 100,000
+    // (0.00001) is the maximum position before Unity warns the user of precision issues.
+    io_PositionWS = lerp(center, io_PositionWS, lerp(1.0, 1.01, max(camera.x, camera.y) * 0.00001));
+}
+
 m_CrestNameSpaceEnd
 
 #endif // CREST_WATER_VERT_HELPERS_H