Sanitize tangents when creating mesh surfaces to avoid triggering the compressed mesh path in the shader

1 files changed, 5 insertions, 0 deletions

diff --git a/scene/resources/immediate_mesh.cpp b/scene/resources/immediate_mesh.cpp
index 0112ffd452..3507df8bd8 100644
--- a/scene/resources/immediate_mesh.cpp
+++ b/scene/resources/immediate_mesh.cpp
@@ -208,6 +208,11 @@ void ImmediateMesh::surface_end() {
 				uint32_t value = 0;
 				value |= (uint16_t)CLAMP(t.x * 65535, 0, 65535);
 				value |= (uint16_t)CLAMP(t.y * 65535, 0, 65535) << 16;
+				if (value == 4294901760) {
+					// (1, 1) and (0, 1) decode to the same value, but (0, 1) messes with our compression detection.
+					// So we sanitize here.
+					value = 4294967295;
+				}
 
 				*tangent = value;
 			}