Commit: 3a1e6bc1d5807b732536c73170f11268fb398726 Author: Aras Pranckevicius Date: Sat Mar 19 16:20:22 2022 -0400 Branches: blender-v3.1-release https://developer.blender.org/rB3a1e6bc1d5807b732536c73170f11268fb398726
Fix T96430: new OBJ exporter wrong normals for non-uniform scale, and wrong face order for negative scale The new 3.1+ OBJ exporter did not have correct logic when faced with non-uniform & mirrored (negative on odd number of axes) object scale: - Normals were not transformed correctly (should use inverse transpose of the matrix), and were not normalized, - Face order was not "flipped" when transform has negative scale on odd number of axes (visible when using "face orientation" viewport overlay). Cherry-picked from 8aa365745a78, with minor conflict fixes. Reviewed By: Howard Trickey Differential Revision: https://developer.blender.org/D14343 =================================================================== M source/blender/io/wavefront_obj/exporter/obj_export_file_writer.cc M source/blender/io/wavefront_obj/exporter/obj_export_file_writer.hh M source/blender/io/wavefront_obj/exporter/obj_export_mesh.cc M source/blender/io/wavefront_obj/exporter/obj_export_mesh.hh M source/blender/io/wavefront_obj/tests/obj_exporter_tests.cc =================================================================== diff --git a/source/blender/io/wavefront_obj/exporter/obj_export_file_writer.cc b/source/blender/io/wavefront_obj/exporter/obj_export_file_writer.cc index 38163af64b6..4eea2e51521 100644 --- a/source/blender/io/wavefront_obj/exporter/obj_export_file_writer.cc +++ b/source/blender/io/wavefront_obj/exporter/obj_export_file_writer.cc @@ -54,56 +54,109 @@ const char *MATERIAL_GROUP_DISABLED = ""; void OBJWriter::write_vert_uv_normal_indices(Span<int> vert_indices, Span<int> uv_indices, - Span<int> normal_indices) const + Span<int> normal_indices, + bool flip) const { BLI_assert(vert_indices.size() == uv_indices.size() && vert_indices.size() == normal_indices.size()); + const int vertex_offset = index_offsets_.vertex_offset + 1; + const int uv_offset = index_offsets_.uv_vertex_offset + 1; + const int normal_offset = index_offsets_.normal_offset + 1; + const int n = vert_indices.size(); file_handler_->write<eOBJSyntaxElement::poly_element_begin>(); - for (int j = 0; j < vert_indices.size(); j++) { - file_handler_->write<eOBJSyntaxElement::vertex_uv_normal_indices>( - vert_indices[j] + index_offsets_.vertex_offset + 1, - uv_indices[j] + index_offsets_.uv_vertex_offset + 1, - normal_indices[j] + index_offsets_.normal_offset + 1); + if (!flip) { + for (int j = 0; j < n; ++j) { + file_handler_->write<eOBJSyntaxElement::vertex_uv_normal_indices>( + vert_indices[j] + vertex_offset, + uv_indices[j] + uv_offset, + normal_indices[j] + normal_offset); + } + } + else { + /* For a transform that is mirrored (negative scale on odd number of axes), + * we want to flip the face index order. Start from the same index, and + * then go backwards. Same logic in other write_*_indices functions below. */ + for (int k = 0; k < n; ++k) { + int j = k == 0 ? 0 : n - k; + file_handler_->write<eOBJSyntaxElement::vertex_uv_normal_indices>( + vert_indices[j] + vertex_offset, + uv_indices[j] + uv_offset, + normal_indices[j] + normal_offset); + } } file_handler_->write<eOBJSyntaxElement::poly_element_end>(); } void OBJWriter::write_vert_normal_indices(Span<int> vert_indices, Span<int> /*uv_indices*/, - Span<int> normal_indices) const + Span<int> normal_indices, + bool flip) const { BLI_assert(vert_indices.size() == normal_indices.size()); + const int vertex_offset = index_offsets_.vertex_offset + 1; + const int normal_offset = index_offsets_.normal_offset + 1; + const int n = vert_indices.size(); file_handler_->write<eOBJSyntaxElement::poly_element_begin>(); - for (int j = 0; j < vert_indices.size(); j++) { - file_handler_->write<eOBJSyntaxElement::vertex_normal_indices>( - vert_indices[j] + index_offsets_.vertex_offset + 1, - normal_indices[j] + index_offsets_.normal_offset + 1); + if (!flip) { + for (int j = 0; j < n; ++j) { + file_handler_->write<eOBJSyntaxElement::vertex_normal_indices>( + vert_indices[j] + vertex_offset, normal_indices[j] + normal_offset); + } + } + else { + for (int k = 0; k < n; ++k) { + int j = k == 0 ? 0 : n - k; + file_handler_->write<eOBJSyntaxElement::vertex_normal_indices>( + vert_indices[j] + vertex_offset, normal_indices[j] + normal_offset); + } } file_handler_->write<eOBJSyntaxElement::poly_element_end>(); } void OBJWriter::write_vert_uv_indices(Span<int> vert_indices, Span<int> uv_indices, - Span<int> /*normal_indices*/) const + Span<int> /*normal_indices*/, + bool flip) const { BLI_assert(vert_indices.size() == uv_indices.size()); + const int vertex_offset = index_offsets_.vertex_offset + 1; + const int uv_offset = index_offsets_.uv_vertex_offset + 1; + const int n = vert_indices.size(); file_handler_->write<eOBJSyntaxElement::poly_element_begin>(); - for (int j = 0; j < vert_indices.size(); j++) { - file_handler_->write<eOBJSyntaxElement::vertex_uv_indices>( - vert_indices[j] + index_offsets_.vertex_offset + 1, - uv_indices[j] + index_offsets_.uv_vertex_offset + 1); + if (!flip) { + for (int j = 0; j < n; ++j) { + file_handler_->write<eOBJSyntaxElement::vertex_uv_indices>(vert_indices[j] + vertex_offset, + uv_indices[j] + uv_offset); + } + } + else { + for (int k = 0; k < n; ++k) { + int j = k == 0 ? 0 : n - k; + file_handler_->write<eOBJSyntaxElement::vertex_uv_indices>(vert_indices[j] + vertex_offset, + uv_indices[j] + uv_offset); + } } file_handler_->write<eOBJSyntaxElement::poly_element_end>(); } void OBJWriter::write_vert_indices(Span<int> vert_indices, Span<int> /*uv_indices*/, - Span<int> /*normal_indices*/) const + Span<int> /*normal_indices*/, + bool flip) const { + const int vertex_offset = index_offsets_.vertex_offset + 1; + const int n = vert_indices.size(); file_handler_->write<eOBJSyntaxElement::poly_element_begin>(); - for (const int vert_index : vert_indices) { - file_handler_->write<eOBJSyntaxElement::vertex_indices>(vert_index + - index_offsets_.vertex_offset + 1); + if (!flip) { + for (int j = 0; j < n; ++j) { + file_handler_->write<eOBJSyntaxElement::vertex_indices>(vert_indices[j] + vertex_offset); + } + } + else { + for (int k = 0; k < n; ++k) { + int j = k == 0 ? 0 : n - k; + file_handler_->write<eOBJSyntaxElement::vertex_indices>(vert_indices[j] + vertex_offset); + } } file_handler_->write<eOBJSyntaxElement::poly_element_end>(); } @@ -297,7 +350,10 @@ void OBJWriter::write_poly_elements(const OBJMesh &obj_mesh_data, last_poly_smooth_group = write_smooth_group(obj_mesh_data, i, last_poly_smooth_group); last_poly_vertex_group = write_vertex_group(obj_mesh_data, i, last_poly_vertex_group); last_poly_mat_nr = write_poly_material(obj_mesh_data, i, last_poly_mat_nr, matname_fn); - (this->*poly_element_writer)(poly_vertex_indices, poly_uv_indices, poly_normal_indices); + (this->*poly_element_writer)(poly_vertex_indices, + poly_uv_indices, + poly_normal_indices, + obj_mesh_data.is_mirrored_transform()); } } diff --git a/source/blender/io/wavefront_obj/exporter/obj_export_file_writer.hh b/source/blender/io/wavefront_obj/exporter/obj_export_file_writer.hh index 7385d9fabe2..1bbdb7a848c 100644 --- a/source/blender/io/wavefront_obj/exporter/obj_export_file_writer.hh +++ b/source/blender/io/wavefront_obj/exporter/obj_export_file_writer.hh @@ -135,7 +135,8 @@ class OBJWriter : NonMovable, NonCopyable { private: using func_vert_uv_normal_indices = void (OBJWriter::*)(Span<int> vert_indices, Span<int> uv_indices, - Span<int> normal_indices) const; + Span<int> normal_indices, + bool flip) const; /** * \return Writer function with appropriate polygon-element syntax. */ @@ -146,25 +147,29 @@ class OBJWriter : NonMovable, NonCopyable { */ void write_vert_uv_normal_indices(Span<int> vert_indices, Span<int> uv_indices, - Span<int> normal_indices) const; + Span<int> normal_indices, + bool flip) const; /** * Write one line of polygon indices as "f v1//vn1 v2//vn2 ...". */ void write_vert_normal_indices(Span<int> vert_indices, Span<int> /*uv_indices*/, - Span<int> normal_indices) const; + Span<int> normal_indices, + bool flip) const; /** * Write one line of polygon indices as "f v1/vt1 v2/vt2 ...". */ void write_vert_uv_indices(Span<int> vert_indices, Span<int> uv_indices, - Span<int> /*normal_indices*/) const; + Span<int> /*normal_indices*/, + bool flip) const; /** * Write one line of polygon indices as "f v1 v2 ...". */ void write_vert_indices(Span<int> vert_indices, Span<int> /*uv_indices*/, - Span<int> /*normal_indices*/) const; + Span<int> /*normal_indices*/, + bool flip) const; }; /** diff --git a/source/blender/io/wavefront_obj/exporter/obj_export_mesh.cc b/source/blender/io/wavefront_obj/exporter/obj_export_mesh.cc index 66f10009875..c1b9b0a8ccf 100644 --- a/source/blender/io/wavefront_obj/exporter/obj_export_mesh.cc +++ b/source/blender/io/wavefront_obj/exporter/obj_export_mesh.cc @@ -125,6 +125,13 @@ void OBJMesh::set_world_axes_transform(const eTransformAxisForward forward, /* mul_m4_m3m4 does not transform last row of obmat, i.e. location data. */ mul_v3_m3v3(world_and_axes_transform_[3], axes_transform, export_object_eval_.obmat[3]); world_and_axes_transform_[3][3] = export_object_eval_.obmat[3][3]; + + /* Normals need inverse transpose of the regular matrix to handle non-uniform scale. */ + float normal_matrix[3][3]; + copy_m3_m4(normal_matrix, world_and_axes_transform_); + @@ Diff output truncated at 10240 characters. @@ _______________________________________________ Bf-blender-cvs mailing list [email protected] List details, subscription details or unsubscribe: https://lists.blender.org/mailman/listinfo/bf-blender-cvs
