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Avoid singularity when generated tangents and validate that tangents …
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…are good enough when using compression
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clayjohn committed Feb 24, 2024
1 parent 16d6142 commit 781cd27
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Showing 5 changed files with 50 additions and 8 deletions.
17 changes: 15 additions & 2 deletions editor/import/3d/editor_import_collada.cpp
Original file line number Diff line number Diff line change
Expand Up @@ -938,11 +938,11 @@ Error ColladaImport::_create_mesh_surfaces(bool p_optimize, Ref<ImporterMesh> &p
if (binormal_src && tangent_src) {
surftool->set_tangent(vertex_array[k].tangent);
} else if (generate_dummy_tangents) {
Vector3 tan = Vector3(0.0, 1.0, 0.0).cross(vertex_array[k].normal);
Vector3 tan = Vector3(vertex_array[k].normal.z, -vertex_array[k].normal.x, vertex_array[k].normal.y).cross(vertex_array[k].normal.normalized()).normalized();
surftool->set_tangent(Plane(tan.x, tan.y, tan.z, 1.0));
}
} else {
// No normals, use a dummy normal since normals will be generated.
// No normals, use a dummy tangent since normals will be generated.
if (generate_dummy_tangents) {
surftool->set_tangent(Plane(1.0, 0.0, 0.0, 1.0));
}
Expand Down Expand Up @@ -1008,6 +1008,19 @@ Error ColladaImport::_create_mesh_surfaces(bool p_optimize, Ref<ImporterMesh> &p
Array d = surftool->commit_to_arrays();
d.resize(RS::ARRAY_MAX);

if (mesh_flags & RS::ARRAY_FLAG_COMPRESS_ATTRIBUTES && (generate_dummy_tangents || generate_tangents)) {
// Compression is enabled, so let's validate that the normals and tangents are correct.
Vector<Vector3> normals = d[Mesh::ARRAY_NORMAL];
Vector<float> tangents = d[Mesh::ARRAY_TANGENT];
for (int vert = 0; vert < normals.size(); vert++) {
Vector3 tan = Vector3(tangents[vert * 4 + 0], tangents[vert * 4 + 1], tangents[vert * 4 + 2]);
if (abs(tan.dot(normals[vert])) > 0.0001) {
// Tangent is not perpendicular to the normal, so we can't use compression.
mesh_flags &= ~RS::ARRAY_FLAG_COMPRESS_ATTRIBUTES;
}
}
}

Array mr;

////////////////////////////
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18 changes: 16 additions & 2 deletions editor/import/3d/resource_importer_obj.cpp
Original file line number Diff line number Diff line change
Expand Up @@ -329,11 +329,11 @@ static Error _parse_obj(const String &p_path, List<Ref<ImporterMesh>> &r_meshes,
surf_tool->set_normal(normals[norm]);
if (generate_tangents && uvs.is_empty()) {
// We can't generate tangents without UVs, so create dummy tangents.
Vector3 tan = Vector3(0.0, 1.0, 0.0).cross(normals[norm]);
Vector3 tan = Vector3(normals[norm].z, -normals[norm].x, normals[norm].y).cross(normals[norm].normalized()).normalized();
surf_tool->set_tangent(Plane(tan.x, tan.y, tan.z, 1.0));
}
} else {
// No normals, use a dummy normal since normals will be generated.
// No normals, use a dummy tangent since normals and tangents will be generated.
if (generate_tangents && uvs.is_empty()) {
// We can't generate tangents without UVs, so create dummy tangents.
surf_tool->set_tangent(Plane(1.0, 0.0, 0.0, 1.0));
Expand Down Expand Up @@ -415,6 +415,20 @@ static Error _parse_obj(const String &p_path, List<Ref<ImporterMesh>> &r_meshes,
mesh->set_surface_name(mesh->get_surface_count() - 1, current_group);
}
Array array = surf_tool->commit_to_arrays();

if (mesh_flags & RS::ARRAY_FLAG_COMPRESS_ATTRIBUTES && generate_tangents) {
// Compression is enabled, so let's validate that the normals and tangents are correct.
Vector<Vector3> norms = array[Mesh::ARRAY_NORMAL];
Vector<float> tangents = array[Mesh::ARRAY_TANGENT];
for (int vert = 0; vert < norms.size(); vert++) {
Vector3 tan = Vector3(tangents[vert * 4 + 0], tangents[vert * 4 + 1], tangents[vert * 4 + 2]);
if (abs(tan.dot(norms[vert])) > 0.0001) {
// Tangent is not perpendicular to the normal, so we can't use compression.
mesh_flags &= ~RS::ARRAY_FLAG_COMPRESS_ATTRIBUTES;
}
}
}

mesh->add_surface(Mesh::PRIMITIVE_TRIANGLES, array, TypedArray<Array>(), Dictionary(), material, name, mesh_flags);
print_verbose("OBJ: Added surface :" + mesh->get_surface_name(mesh->get_surface_count() - 1));

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15 changes: 14 additions & 1 deletion modules/gltf/gltf_document.cpp
Original file line number Diff line number Diff line change
Expand Up @@ -2813,7 +2813,7 @@ Error GLTFDocument::_parse_meshes(Ref<GLTFState> p_state) {

Vector<Vector3> normals = array[Mesh::ARRAY_NORMAL];
for (int k = 0; k < vertex_num; k++) {
Vector3 tan = Vector3(0.0, 1.0, 0.0).cross(normals[k]);
Vector3 tan = Vector3(normals[i].z, -normals[i].x, normals[i].y).cross(normals[k].normalized()).normalized();
tangentsw[k * 4 + 0] = tan.x;
tangentsw[k * 4 + 1] = tan.y;
tangentsw[k * 4 + 2] = tan.z;
Expand All @@ -2839,6 +2839,19 @@ Error GLTFDocument::_parse_meshes(Ref<GLTFState> p_state) {
}
array = mesh_surface_tool->commit_to_arrays();

if ((flags & RS::ARRAY_FLAG_COMPRESS_ATTRIBUTES) && a.has("NORMAL") && (a.has("TANGENT") || generate_tangents)) {
// Compression is enabled, so let's validate that the normals and tangents are correct.
Vector<Vector3> normals = array[Mesh::ARRAY_NORMAL];
Vector<float> tangents = array[Mesh::ARRAY_TANGENT];
for (int vert = 0; vert < normals.size(); vert++) {
Vector3 tan = Vector3(tangents[vert * 4 + 0], tangents[vert * 4 + 1], tangents[vert * 4 + 2]);
if (abs(tan.dot(normals[vert])) > 0.0001) {
// Tangent is not perpendicular to the normal, so we can't use compression.
flags &= ~RS::ARRAY_FLAG_COMPRESS_ATTRIBUTES;
}
}
}

Array morphs;
//blend shapes
if (p.has("targets")) {
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2 changes: 1 addition & 1 deletion scene/resources/immediate_mesh.cpp
Original file line number Diff line number Diff line change
Expand Up @@ -208,7 +208,7 @@ void ImmediateMesh::surface_end() {
if (uses_tangents) {
t = tangents[i].normal.octahedron_tangent_encode(tangents[i].d);
} else {
Vector3 tan = Vector3(0.0, 1.0, 0.0).cross(normals[i].normalized());
Vector3 tan = Vector3(normals[i].z, -normals[i].x, normals[i].y).cross(normals[i].normalized()).normalized();
t = tan.octahedron_tangent_encode(1.0);
}

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6 changes: 4 additions & 2 deletions servers/rendering_server.cpp
Original file line number Diff line number Diff line change
Expand Up @@ -566,7 +566,8 @@ Error RenderingServer::_surface_set_data(Array p_arrays, uint64_t p_format, uint
float angle;
Vector3 axis;
// Generate an arbitrary vector that is tangential to normal.
Vector3 tan = Vector3(0.0, 1.0, 0.0).cross(normal_src[i].normalized());
// This assumes that the normal is never (0,0,0).
Vector3 tan = Vector3(normal_src[i].z, -normal_src[i].x, normal_src[i].y).cross(normal_src[i].normalized()).normalized();
Vector4 tangent = Vector4(tan.x, tan.y, tan.z, 1.0);
_get_axis_angle(normal_src[i], tangent, angle, axis);

Expand Down Expand Up @@ -689,7 +690,8 @@ Error RenderingServer::_surface_set_data(Array p_arrays, uint64_t p_format, uint
// Set data for tangent.
for (int i = 0; i < p_vertex_array_len; i++) {
// Generate an arbitrary vector that is tangential to normal.
Vector3 tan = Vector3(0.0, 1.0, 0.0).cross(normal_src[i].normalized());
// This assumes that the normal is never (0,0,0).
Vector3 tan = Vector3(normal_src[i].z, -normal_src[i].x, normal_src[i].y).cross(normal_src[i].normalized()).normalized();
Vector2 res = tan.octahedron_tangent_encode(1.0);
uint16_t vector[2] = {
(uint16_t)CLAMP(res.x * 65535, 0, 65535),
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