Fix T101685: OBJ importer does not assign proper material if "usemtl" is before "o"

The importer logic was wrongly resetting "current material name"
upon encountering a new object ("o" command). However as per OBJ
specification, this is incorrect:

> Specifies the material name for the element following it. Once a
> material is assigned, it cannot be turned off; it can only be
> changed.

Fixes T101685. Test coverage for this was added in svn tests repo.
This commit is contained in:
Aras Pranckevicius
2022-10-09 21:21:31 +03:00
parent c2fb85282d
commit bd2f002e71

View File

@@ -508,6 +508,15 @@ void OBJParser::parse(Vector<std::unique_ptr<Geometry>> &r_all_geometries,
}
/* Faces. */
else if (parse_keyword(p, end, "f")) {
/* If we don't have a material index assigned yet, get one.
* It means "usemtl" state came from the previous object. */
if (state_material_index == -1 && !state_material_name.empty() &&
curr_geom->material_indices_.is_empty()) {
curr_geom->material_indices_.add_new(state_material_name, 0);
curr_geom->material_order_.append(state_material_name);
state_material_index = 0;
}
geom_add_polygon(curr_geom,
p,
end,
@@ -524,7 +533,10 @@ void OBJParser::parse(Vector<std::unique_ptr<Geometry>> &r_all_geometries,
else if (parse_keyword(p, end, "o")) {
state_shaded_smooth = false;
state_group_name = "";
state_material_name = "";
/* Reset object-local material index that's used in face infos.
* Note: do not reset the material name; that has to carry over
* into the next object if needed. */
state_material_index = -1;
curr_geom = create_geometry(
curr_geom, GEOM_MESH, StringRef(p, end).trim(), r_all_geometries);
}