Check textures available before loading

src/models.c

@@ -2846,21 +2846,21 @@ static Model LoadOBJ(const char *fileName)
             } tinyobj_material_t;
             */
 
-            model.materials[m].maps[MAP_DIFFUSE].texture = LoadTexture(materials[m].diffuse_texname);  //char *diffuse_texname; // map_Kd
+            if (materials[m].diffuse_texname != NULL) model.materials[m].maps[MAP_DIFFUSE].texture = LoadTexture(materials[m].diffuse_texname);  //char *diffuse_texname; // map_Kd
             model.materials[m].maps[MAP_DIFFUSE].color = (Color){ (float)(materials[m].diffuse[0]*255.0f), (float)(materials[m].diffuse[1]*255.0f), (float)(materials[m].diffuse[2]*255.0f), 255 }; //float diffuse[3];
             model.materials[m].maps[MAP_DIFFUSE].value = 0.0f;
 
-            model.materials[m].maps[MAP_SPECULAR].texture = LoadTexture(materials[m].specular_texname);  //char *specular_texname; // map_Ks
+            if (materials[m].specular_texname != NULL) model.materials[m].maps[MAP_SPECULAR].texture = LoadTexture(materials[m].specular_texname);  //char *specular_texname; // map_Ks
             model.materials[m].maps[MAP_SPECULAR].color = (Color){ (float)(materials[m].specular[0]*255.0f), (float)(materials[m].specular[1]*255.0f), (float)(materials[m].specular[2]*255.0f), 255 }; //float specular[3];
             model.materials[m].maps[MAP_SPECULAR].value = 0.0f;
 
-            model.materials[m].maps[MAP_NORMAL].texture = LoadTexture(materials[m].bump_texname);  //char *bump_texname; // map_bump, bump
+            if (materials[m].bump_texname != NULL) model.materials[m].maps[MAP_NORMAL].texture = LoadTexture(materials[m].bump_texname);  //char *bump_texname; // map_bump, bump
             model.materials[m].maps[MAP_NORMAL].color = WHITE;
             model.materials[m].maps[MAP_NORMAL].value = materials[m].shininess;
 
             model.materials[m].maps[MAP_EMISSION].color = (Color){ (float)(materials[m].emission[0]*255.0f), (float)(materials[m].emission[1]*255.0f), (float)(materials[m].emission[2]*255.0f), 255 }; //float emission[3];
 
-            model.materials[m].maps[MAP_HEIGHT].texture = LoadTexture(materials[m].displacement_texname);  //char *displacement_texname; // disp
+            if (materials[m].displacement_texname != NULL) model.materials[m].maps[MAP_HEIGHT].texture = LoadTexture(materials[m].displacement_texname);  //char *displacement_texname; // disp
         }
 
         tinyobj_attrib_free(&attrib);