Port over #127

CHANGES.md

@@ -11,6 +11,7 @@ Change Log
 * Fixed loading mtllib paths that contain spaces. [#163](https://github.com/AnalyticalGraphicsInc/obj2gltf/pull/163)
 * Attempt to load missing materials and textures from within the same directory as the obj. [#163](https://github.com/AnalyticalGraphicsInc/obj2gltf/pull/163)
 * Fixed handling of `usemtl` when appearing before an `o` or `g` token. [#163](https://github.com/AnalyticalGraphicsInc/obj2gltf/pull/163)
+* Fixed handling of materials where the diffuse and ambient texture are the same. [#163](https://github.com/AnalyticalGraphicsInc/obj2gltf/pull/163)
 
 ### 1.3.4 2018-10-16
 

lib/loadMtl.js

@@ -86,10 +86,23 @@ function loadMtl(mtlPath) {
 
     return readLines(mtlPath, parseLine)
         .then(function() {
+            cleanupMaterials(materials);
             return materials;
         });
 }
 
+function cleanupMaterials(materials) {
+    for (var name in materials) {
+        if (materials.hasOwnProperty(name)) {
+            var material = materials[name];
+            if (material.diffuseTexture === material.ambientTexture) {
+                // OBJ models are often exported with the same texture in the diffuse and ambient slots but this is usually not desirable
+                material.ambientTexture = undefined;
+            }
+        }
+    }
+}
+
 function normalizeTexturePath(texturePath, mtlDirectory) {
     // Removes texture options from texture name
     // Assumes no spaces in texture name

specs/data/box-diffuse-ambient-same/box-diffuse-ambient-same.mtl

@@ -0,0 +1,14 @@
+# Blender MTL File: 'box.blend'
+# Material Count: 1
+
+newmtl Material
+Ns 96.078431
+Ka 0.000000 0.000000 0.000000
+Kd 0.640000 0.640000 0.640000
+Ks 0.500000 0.500000 0.500000
+Ke 0.000000 0.000000 0.000000
+Ni 1.000000
+d 1.000000
+illum 2
+map_Kd cesium.png
+map_Ka cesium.png

specs/data/box-diffuse-ambient-same/box-diffuse-ambient-same.obj

@@ -0,0 +1,46 @@
+# Blender v2.78 (sub 0) OBJ File: 'box.blend'
+# www.blender.org
+mtllib box-diffuse-ambient-same.mtl
+o Cube
+v -1.000000 -1.000000 1.000000
+v -1.000000 1.000000 1.000000
+v -1.000000 -1.000000 -1.000000
+v -1.000000 1.000000 -1.000000
+v 1.000000 -1.000000 1.000000
+v 1.000000 1.000000 1.000000
+v 1.000000 -1.000000 -1.000000
+v 1.000000 1.000000 -1.000000
+vt 0.0000 0.0000
+vt 1.0000 0.0000
+vt 1.0000 1.0000
+vt 0.0000 1.0000
+vt 0.0000 0.0000
+vt 1.0000 0.0000
+vt 1.0000 1.0000
+vt 0.0000 1.0000
+vt 0.0000 0.0000
+vt 1.0000 0.0000
+vt 1.0000 1.0000
+vt 0.0000 1.0000
+vt 0.0000 0.0000
+vt 1.0000 0.0000
+vt 1.0000 1.0000
+vt 0.0000 1.0000
+vt 1.0000 0.0000
+vt 1.0000 1.0000
+vt 0.0000 0.0000
+vt 0.0000 1.0000
+vn -1.0000 0.0000 0.0000
+vn 0.0000 0.0000 -1.0000
+vn 1.0000 0.0000 0.0000
+vn 0.0000 0.0000 1.0000
+vn 0.0000 -1.0000 0.0000
+vn 0.0000 1.0000 0.0000
+usemtl Material
+s off
+f 1/1/1 2/2/1 4/3/1 3/4/1
+f 3/5/2 4/6/2 8/7/2 7/8/2
+f 7/9/3 8/10/3 6/11/3 5/12/3
+f 5/13/4 6/14/4 2/15/4 1/16/4
+f 3/5/5 7/17/5 5/18/5 1/16/5
+f 8/19/6 4/6/6 2/15/6 6/20/6

specs/lib/loadMtlSpec.js

@@ -3,6 +3,7 @@ var path = require('path');
 var loadMtl = require('../../lib/loadMtl');
 
 var complexMaterialUrl = 'specs/data/box-complex-material/box-complex-material.mtl';
+var diffuseAmbientSameMaterialUrl = 'specs/data/box-diffuse-ambient-same/box-diffuse-ambient-same.mtl';
 var multipleMaterialsUrl = 'specs/data/box-multiple-materials/box-multiple-materials.mtl';
 var texturedWithOptionsMaterialUrl = 'specs/data/box-texture-options/box-texture-options.mtl';
 
@@ -63,4 +64,14 @@ describe('loadMtl', function() {
                 expect(material.doubleSided).toBe(true);
             }), done).toResolve();
     });
+
+    it('ambient texture is ignored if it is the same as the diffuse texture', function(done) {
+        expect(loadMtl(diffuseAmbientSameMaterialUrl, options)
+            .then(function(materials) {
+                expect(Object.keys(materials).length).toBe(1);
+                var material = materials['Material'];
+                expect(material.diffuseTexture).toBeDefined();
+                expect(material.ambientTexture).toBeUndefined();
+            }), done).toResolve();
+    });
 });