fixed wavefront when negative vertex index

Author: andresoviedo

README.md

@@ -180,6 +180,8 @@ ChangeLog
 
 (f) fixed, (i) improved, (n) new feature
 
+- 2.5.1 (20/05/2019)
+  - (f) wavefront loader fixed for faces point to negative indices
 - 2.5.0 (19/05/2019)
   - (n) new blending toggle
   - (n) new color toggle

app/build/outputs/apk/release/app-release.apk

@@ -143,6 +143,8 @@ protected Void doInBackground(Void... params) {
                     try {
                         // this has heterogeneous faces
                         Object3DData obj53 = Object3DBuilder.loadV5(parent, Uri.parse("assets://assets/models/ToyPlane.obj"));
+                        InputStream open = ContentUtils.getInputStream(Uri.parse("assets://assets/models/"+obj53.getTextureFile()));
+                        obj53.setTextureData(IOUtils.read(open));
                         obj53.centerAndScale(2.0f);
                         obj53.setPosition(new float[] { 2f, 0f, 0f });
                         obj53.setColor(new float[] { 1.0f, 1.0f, 1f, 1.0f });

app/src/main/java/org/andresoviedo/app/model3D/demo/ExampleSceneLoader.java

@@ -576,14 +576,8 @@ public static Object3DData generateArrays(Object3DData obj) throws IOException {
 				}
 			}
 			if (texture != null) {
-			    Log.i("Object3DBuilder","Loading texture "+texture);
-			    InputStream is = ContentUtils.getInputStream(texture);
-			    if (is != null) {
-                    textureData = IOUtils.read(is);
-                    is.close();
-                } else {
-			        obj.addError("Texture '"+texture+"' not found in provided files");
-                }
+				obj.setTextureFile(texture);
+			    Log.i("Object3DBuilder","Texture "+texture);
 			} else {
 				Log.i("Object3DBuilder", "Found material(s) but no texture");
 			}

engine/src/main/java/org/andresoviedo/android_3d_model_engine/services/Object3DBuilder.java

@@ -76,6 +76,8 @@ public class WavefrontLoader {
 	int numTextures = 0;
 	int numNormals = 0;
 	int numFaces = 0;
+	int numPolygon = 0;
+	int numTriangles = 0;
 	int numVertsReferences = 0;
 
 	// buffers
@@ -187,6 +189,8 @@ public void analyzeModel(InputStream is) {
 						numFaces += (faceSize - 2);
 						// (faceSize-2)x3 = converting polygon to triangles
 						numVertsReferences += (faceSize - 2) * 3;
+						numPolygon += (faceSize > 3)? 1 : 0;
+						numTriangles += (faceSize == 3)? 1 : 0;
 					} else if (line.startsWith("mtllib ")) // build material
 					{
 						materials = new Materials(line.substring(7));
@@ -219,6 +223,8 @@ else if (line.charAt(0) == 'o') // object group
 
 		Log.i("WavefrontLoader","Number of vertices:"+numVerts);
 		Log.i("WavefrontLoader","Number of faces:"+numFaces);
+		Log.i("WavefrontLoader","- Number of polygons:"+numPolygon);
+		Log.i("WavefrontLoader","- Number of triangles:"+numTriangles);
 	}
 
 	/**
@@ -850,6 +856,7 @@ public static class Faces {
 		 */
 		public ArrayList<int[]> facesNormIdxs;
 
+        private FloatBuffer vertex;
 		private FloatBuffer normals;
 		private ArrayList<Tuple3> texCoords;
 
@@ -869,6 +876,7 @@ public Faces(int numFaces){
 
 		Faces(int totalFaces, IntBuffer buffer, FloatBuffer vs, FloatBuffer ns, ArrayList<Tuple3> ts) {
 			this.totalFaces = totalFaces;
+			vertex = vs;
 			normals = ns;
 			texCoords = ts;
 
@@ -951,10 +959,6 @@ public boolean addFace(String line) {
 					// the token
 
 					int vertIdx = Integer.parseInt(faceTokens[0]);
-					/*if (vertIdx > 65535){
-						Log.e("WavefrontLoader","Ignoring face because its out of range (>65535)");
-						continue;
-					}*/
 					if (numSeps > 1){
 						if (vt == null)	vt = new int[3];
 						try{
@@ -974,7 +978,12 @@ public boolean addFace(String line) {
 					// add 0's if the vt or vn index values are missing;
 					// 0 is a good choice since real indices start at 1
 
-					if (WavefrontLoader.INDEXES_START_AT_1) {
+                    if (vertIdx < 0){
+					    vertIdx = this.vertex.capacity()/3+vertIdx;
+                        if (vt != null)	vt[faceIndex] = texCoords.size() + vt[faceIndex];
+                        if (vn != null) vn[faceIndex] = normals.capacity()/3 + vn[faceIndex];
+                    }
+					else if (WavefrontLoader.INDEXES_START_AT_1) {
 						vertIdx--;
 						if (vt != null)	vt[faceIndex] = vt[faceIndex] - 1;
 						if (vn != null) vn[faceIndex] = vn[faceIndex] - 1;