Detect 'insane' normals in checkMeshNormals.

Detect non-zero normals which point in the opposite direction from the
face plane normal.
This commit is contained in:
Dmitry Kostenko 2021-11-08 23:13:50 +01:00 committed by x2048
parent 54dccc480e
commit 1175f48d05

@ -331,6 +331,9 @@ void recalculateBoundingBox(scene::IMesh *src_mesh)
bool checkMeshNormals(scene::IMesh *mesh)
{
// Assume correct normals if this many first faces get it right.
static const u16 MAX_FACES_TO_CHECK = 9;
u32 buffer_count = mesh->getMeshBufferCount();
for (u32 i = 0; i < buffer_count; i++) {
@ -344,6 +347,19 @@ bool checkMeshNormals(scene::IMesh *mesh)
if (!std::isfinite(length) || length < 1e-10f)
return false;
const u16 count = MYMIN(MAX_FACES_TO_CHECK * 3, buffer->getIndexCount());
for (u16 i = 0; i < count; i += 3) {
core::plane3df plane(buffer->getPosition(buffer->getIndices()[i]),
buffer->getPosition(buffer->getIndices()[i+1]),
buffer->getPosition(buffer->getIndices()[i+2]));
for (u16 j = 0; j < 3; j++)
if (plane.Normal.dotProduct(buffer->getNormal(buffer->getIndices()[j])) < 0)
return false;
}
}
return true;