OBJLoader enhancement: named groups support

jme3-core/build.gradle

@@ -17,6 +17,10 @@ sourceSets {
     }
 }
 
+dependencies {
+    testCompile project(':jme3-testdata')
+}
+
 task updateVersionPropertiesFile {
     def versionFile = file('src/main/resources/com/jme3/system/version.properties')
     def versionFileText = "# THIS IS AN AUTO-GENERATED FILE..\n" +

jme3-core/src/plugins/java/com/jme3/scene/plugins/MTLLoader.java

@@ -152,6 +152,7 @@ protected void createMaterial(){
             material.setFloat("AlphaDiscardThreshold", 0.01f);
         }
 
+        material.setName(matName);
         matList.put(matName, material);
     }
 

jme3-core/src/plugins/java/com/jme3/scene/plugins/OBJLoader.java

@@ -66,10 +66,9 @@ public final class OBJLoader implements AssetLoader {
     protected final ArrayList<Vector3f> verts = new ArrayList<Vector3f>();
     protected final ArrayList<Vector2f> texCoords = new ArrayList<Vector2f>();
     protected final ArrayList<Vector3f> norms = new ArrayList<Vector3f>();
-
-    protected final ArrayList<Face> faces = new ArrayList<Face>();
-    protected final HashMap<String, ArrayList<Face>> matFaces = new HashMap<String, ArrayList<Face>>();
-
+
+    private final ArrayList<Group> groups = new ArrayList<Group>();
+
     protected String currentMatName;
     protected String currentObjectName;
 
@@ -87,6 +86,16 @@ public final class OBJLoader implements AssetLoader {
     protected String objName;
     protected Node objNode;
 
+    private static class Group {
+        private String name;
+        private final ArrayList<Face> faces = new ArrayList<Face>();
+        private final HashMap<String, ArrayList<Face>> matFaces = new HashMap<String, ArrayList<Face>>();
+
+        public Group(final String name) {
+            this.name = name;
+        }
+    }
+
     protected static class Vertex {
 
         Vector3f v;
@@ -164,8 +173,7 @@ public void reset(){
         verts.clear();
         texCoords.clear();
         norms.clear();
-        faces.clear();
-        matFaces.clear();
+        groups.clear();
 
         vertIndexMap.clear();
         indexVertMap.clear();
@@ -289,10 +297,17 @@ protected void readFace(){
             f.verticies[i] = vertList.get(i);
         }
 
-        if (matList != null && matFaces.containsKey(currentMatName)){
-            matFaces.get(currentMatName).add(f);
+        Group group = groups.get(groups.size() - 1);
+
+        if (currentMatName != null && matList != null && matList.containsKey(currentMatName)){
+            ArrayList<Face> matFaces = group.matFaces.get(currentMatName);
+            if (matFaces == null) {
+                matFaces = new ArrayList<Face>();
+                group.matFaces.put(currentMatName, matFaces);
+            }
+            matFaces.add(f);
         }else{
-            faces.add(f); // faces that belong to the default material
+            group.faces.add(f); // faces that belong to the default material
         }
     }
 
@@ -337,13 +352,6 @@ protected void loadMtlLib(String name) throws IOException{
         } catch (AssetNotFoundException ex){
             logger.log(Level.WARNING, "Cannot locate {0} for model {1}", new Object[]{name, key});
         }
-
-        if (matList != null){
-            // create face lists for every material
-            for (String matName : matList.keySet()){
-                matFaces.put(matName, new ArrayList<Face>());
-            }
-        }
     }
 
     protected boolean nextStatement(){
@@ -387,8 +395,14 @@ protected boolean readLine() throws IOException{
             // specify MTL lib to use for this OBJ file
             String mtllib = scan.nextLine().trim();
             loadMtlLib(mtllib);
-        }else if (cmd.equals("s") || cmd.equals("g")){
+        }else if (cmd.equals("s")) {
+            logger.log(Level.WARNING, "smoothing groups are not supported, statement ignored: {0}", cmd);
+            return nextStatement();
+        }else if (cmd.equals("mg")) {
+            logger.log(Level.WARNING, "merge groups are not supported, statement ignored: {0}", cmd);
             return nextStatement();
+        }else if (cmd.equals("g")) {
+            groups.add(new Group(scan.nextLine().trim()));
         }else{
             // skip entire command until next line
             logger.log(Level.WARNING, "Unknown statement in OBJ! {0}", cmd);
@@ -565,11 +579,14 @@ public Object load(AssetInfo info) throws IOException{
         }
 
         objNode = new Node(objName + "-objnode");
+
+        Group defaultGroupStub = new Group(null);
+        groups.add(defaultGroupStub);
 
         if (!(info.getKey() instanceof ModelKey))
             throw new IllegalArgumentException("Model assets must be loaded using a ModelKey");
 
-        InputStream in = null; 
+        InputStream in = null;
         try {
             in = info.openStream();
 
@@ -583,25 +600,43 @@ public Object load(AssetInfo info) throws IOException{
             }
         }
 
-        if (matFaces.size() > 0){
-            for (Entry<String, ArrayList<Face>> entry : matFaces.entrySet()){
-                ArrayList<Face> materialFaces = entry.getValue();
-                if (materialFaces.size() > 0){
-                    Geometry geom = createGeometry(materialFaces, entry.getKey());
+        for (Group group : groups) {
+            if (group == defaultGroupStub) {
+                materializeGroup(group, objNode);
+            } else {
+                Node groupNode = new Node(group.name);
+                materializeGroup(group, groupNode);
+                if (groupNode.getQuantity() == 1) {
+                    Spatial geom = groupNode.getChild(0);
+                    geom.setName(groupNode.getName());
                     objNode.attachChild(geom);
+                } else if (groupNode.getQuantity() > 1) {
+                    objNode.attachChild(groupNode);
                 }
             }
-        }else if (faces.size() > 0){
-            // generate final geometry
-            Geometry geom = createGeometry(faces, null);
-            objNode.attachChild(geom);
         }
 
         if (objNode.getQuantity() == 1)
             // only 1 geometry, so no need to send node
-            return objNode.getChild(0); 
+            return objNode.getChild(0);
         else
             return objNode;
     }
-
+
+    private void materializeGroup(Group group, Node container) throws IOException {
+        if (group.matFaces.size() > 0) {
+            for (Entry<String, ArrayList<Face>> entry : group.matFaces.entrySet()){
+                ArrayList<Face> materialFaces = entry.getValue();
+                if (materialFaces.size() > 0){
+                    Geometry geom = createGeometry(materialFaces, entry.getKey());
+                    container.attachChild(geom);
+                }
+            }
+        } else if (group.faces.size() > 0) {
+            // generate final geometry
+            Geometry geom = createGeometry(group.faces, null);
+            container.attachChild(geom);
+        }
+    }
+
 }

jme3-core/src/test/java/com/jme3/scene/plugins/OBJLoaderTest.java

@@ -0,0 +1,106 @@
+/*
+ * Copyright (c) 2009-2020 jMonkeyEngine
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *
+ * * Redistributions of source code must retain the above copyright
+ *   notice, this list of conditions and the following disclaimer.
+ *
+ * * Redistributions in binary form must reproduce the above copyright
+ *   notice, this list of conditions and the following disclaimer in the
+ *   documentation and/or other materials provided with the distribution.
+ *
+ * * Neither the name of 'jMonkeyEngine' nor the names of its contributors
+ *   may be used to endorse or promote products derived from this software
+ *   without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
+ * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+ * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
+ * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+ * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+ * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
+ * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
+ * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
+ * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+ * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+package com.jme3.scene.plugins;
+
+import com.jme3.asset.AssetInfo;
+import com.jme3.asset.AssetLoader;
+import com.jme3.asset.AssetManager;
+import com.jme3.asset.ModelKey;
+import com.jme3.scene.Geometry;
+import com.jme3.scene.Node;
+import com.jme3.scene.Spatial;
+import com.jme3.system.TestUtil;
+import com.jme3.texture.Image;
+import org.junit.Before;
+import org.junit.Test;
+
+import static org.junit.Assert.assertEquals;
+
+public class OBJLoaderTest {
+    private AssetManager assetManager;
+
+    @Before
+    public void init() {
+        assetManager = TestUtil.createAssetManager();
+        // texture loaders are outside of core, so creating stub
+        assetManager.registerLoader(PngLoaderStub.class, "png");
+
+    }
+
+    @Test
+    public void testHappyPath() {
+        Node scene = (Node) assetManager.loadModel(new ModelKey("OBJLoaderTest/TwoChairs.obj"));
+        String sceneAsString = toDiffFriendlyString("", scene);
+        System.out.println(sceneAsString);
+        String expectedText = "" +
+            // generated root name (as before named groups support)
+            "TwoChairs-objnode\n" +
+            // unnamed geometry with generated name (as before named groups support).
+            // actually it's partially smoothed, but this fact is ignored.
+            "  TwoChairs-geom-0 (material: dot_purple)\n" +
+            // named group as Geometry
+            "  Chair 2 (material: dot_purple)\n" +
+            // named group as Geometry
+            "  Pillow 2 (material: dot_red)\n" +
+            // named group as node with two dufferent Geometry instances,
+            // because two materials are used (as before named groups support)
+            "  Podium\n" +
+            "    TwoChairs-geom-3 (material: dot_red)\n" +
+            "    TwoChairs-geom-4 (material: dot_blue)\n" +
+            // named group as Geometry
+            "  Pillow 1 (material: dot_green)";
+        assertEquals(expectedText, sceneAsString.trim());
+    }
+
+    private static String toDiffFriendlyString(String indent, Spatial spatial) {
+        if (spatial instanceof Geometry) {
+            return indent + spatial.getName() + " (material: "+((Geometry) spatial).getMaterial().getName()+")\n";
+        }
+        if (spatial instanceof Node) {
+            StringBuilder s = new StringBuilder();
+            s.append(indent).append(spatial.getName()).append("\n");
+            Node node = (Node) spatial;
+            for (final Spatial child : node.getChildren()) {
+                s.append(toDiffFriendlyString(indent + "  ", child));
+            }
+            return s.toString();
+        }
+        return indent + spatial + "\n";
+    }
+
+    public static class PngLoaderStub implements AssetLoader {
+        @Override
+        public Object load(final AssetInfo assetInfo) {
+            return new Image();
+        }
+    }
+}