From fcaf4839bb9e2bbca8c339ec554d9e386f6c6cd1 Mon Sep 17 00:00:00 2001
From: Iain <iainrobert.maciver@gmail.com>
Date: Sun, 31 Mar 2019 13:56:04 +0100
Subject: [PATCH 1/2] Fix material changes within an object being ignored

Previously, a single object would always create a single model with the
last specified material. A usemtl statement in the middle of an object
will now emit a model at that point (with the previous material).
---
 src/lib.rs | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/src/lib.rs b/src/lib.rs
index 7f47bd1..dec232b 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -692,6 +692,17 @@ pub fn load_obj_buf<B, ML>(reader: &mut B, material_loader: ML) -> LoadResult
             }
             Some("usemtl") => {
                 if let Some(mat_name) = words.next() {
+                    // As materials are returned per-model, a new material within an object
+                    // has to emit a new model with the same name but different material
+                    if !tmp_faces.is_empty() {
+                        models.push(Model::new(export_faces(&tmp_pos,
+                                                            &tmp_texcoord,
+                                                            &tmp_normal,
+                                                            &tmp_faces,
+                                                            mat_id),
+                                            name.clone()));
+                        tmp_faces.clear();
+                    }
                     match mat_map.get(mat_name) {
                         Some(m) => mat_id = Some(*m),
                         None => {

From ac912d398611510663c4fba140fd502f31d0e6b4 Mon Sep 17 00:00:00 2001
From: Iain <iainrobert.maciver@gmail.com>
Date: Tue, 2 Apr 2019 09:36:35 +0100
Subject: [PATCH 2/2] Fix emitting multiple models for repeat usemtl statements

---
 src/lib.rs | 16 +++++++---------
 1 file changed, 7 insertions(+), 9 deletions(-)

diff --git a/src/lib.rs b/src/lib.rs
index dec232b..8f5fa81 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -692,9 +692,10 @@ pub fn load_obj_buf<B, ML>(reader: &mut B, material_loader: ML) -> LoadResult
             }
             Some("usemtl") => {
                 if let Some(mat_name) = words.next() {
+                    let new_mat = mat_map.get(mat_name).cloned();
                     // As materials are returned per-model, a new material within an object
                     // has to emit a new model with the same name but different material
-                    if !tmp_faces.is_empty() {
+                    if mat_id != new_mat && !tmp_faces.is_empty() {
                         models.push(Model::new(export_faces(&tmp_pos,
                                                             &tmp_texcoord,
                                                             &tmp_normal,
@@ -703,15 +704,12 @@ pub fn load_obj_buf<B, ML>(reader: &mut B, material_loader: ML) -> LoadResult
                                             name.clone()));
                         tmp_faces.clear();
                     }
-                    match mat_map.get(mat_name) {
-                        Some(m) => mat_id = Some(*m),
-                        None => {
-                            mat_id = None;
-                            println!("Warning: Object {} refers to unfound material: {}",
-                                     name,
-                                     mat_name);
-                        }
+                    if new_mat.is_none() {
+                        println!("Warning: Object {} refers to unfound material: {}",
+                                        name,
+                                        mat_name);
                     }
+                    mat_id = new_mat;
                 } else {
                     return Err(LoadError::MaterialParseError);
                 }