
## OBJ File Import

To use it, you just have to reference the loader file:

```
<script src="babylon.js"></script>
<script src="babylon.objFileLoader.js"></script>
```
You can find it [here](https://github.com/BabylonJS/Babylon.js/tree/master/dist/preview%20release/loaders)


If you are using ES6 imports via NPM, you need to reference with side-effects:
```
import 'babylonjs-loaders'
```

You can read more about [NPM support](/divingDeeper/developWithBjs/npmSupport)

### Load
See [how to load from any file type](/divingDeeper/importers/loadingFileTypes)
Babylon.js will know how to load the obj file and its mtl file automatically: 

## Good things to know
* Your model doesn't have to be triangulated, as this loader will do it automatically.
* A Babylon.Mesh will be created for each object/group
* The obj model should be exported with -Z axis forward, and Y axis upward to be compatible with Babylon.js

![Axis](/img/how_to/import-obj/axys.jpg)

* By default, due to optimization in the code for loading time, UVs problems can appear, like this :

![Batman UVs problem](/img/how_to/import-obj/uv-issue.jpg)

If you meet this problem, set the variable:
```
BABYLON.OBJFileLoader.OPTIMIZE_WITH_UV = true;
```
Then, you'll have a better texture, but with a longer loading.

![Batman UVs ok](/img/how_to/import-obj/uv-fixed.jpg)

Depending on the modeling program you export your OBJ files from, textures may appear distorted or inverted. As a workaround, you can modify your imported model's UV coordinate scale via setting the variable:
```
BABYLON.OBJFileLoader.UV_SCALE = new BABYLON.Vector2(xValue, yValue)
```

Although not part of Wavefront OBJ file format, some OBJ files include vertex colors. If you are loading such a file and want vertices with colors, set the variable:
```
BABYLON.OBJFileLoader.IMPORT_VERTEX_COLORS = true;
```

If you have an OBJ file without normals or wish to have them calculated for you, set the variable:
```
BABYLON.OBJFileLoader.COMPUTE_NORMALS = true;
```

When using OPTIMIZE_WITH_UV = true you may experience some discontinuities in shading. Setting OPTIMIZE_NORMALS will help with this problem:
```
BABYLON.OBJFileLoader.OPTIMIZE_NORMALS = true;
```

To have your imported model inverted on the y-axis, set the variable:
```
BABYLON.OBJFileLoader.INVERT_Y = true;
```

To invert your imported textures on the y-axis, set the variable:
```
BABYLON.OBJFileLoader.INVERT_TEXTURE_Y = true;
```

By default if a MTL file cannot be loaded (missing/error) it will silently fail.  The model will still be loaded, but if you want to enforce a stricter loading of materials you can use onSuccess() and onError() callbacks accordingly.  Set the variable:
```
BABYLON.OBJFileLoader.MATERIAL_LOADING_FAILS_SILENTLY = false;
```

If a MTL is defined in your OBJ and you wish to have it ignored, set the variable:
```
BABYLON.OBJFileLoader.SKIP_MATERIALS = true;
```

## Supported
* Object/group
* Geometric vertex
    * colors
* Faces
    * triangles
    * quads
    * polygons
* Colors
    * diffuseColor
    * ambientColor
    * specularColor
    * specularPower
    * alpha
* Textures
    * ambientTexture
    * diffuseTexture
    * specularTexture
    * bumpTexture
    * opacityTexture
* Multimaterial
	* For each material defined in the same mesh, it creates a new BABYLON.Mesh.
	* The name of the created BABYLON.Mesh follows this syntax: meshName_mmX 
	* X is the nth BABYLON.Mesh created with this method

## Not supported currently
* Smoothing groups (s parameter in OBJ file)
* Illumination (illum parameter in MTL file)
* The differents options for loading textures in MTL file.
* A good description about MTL files and their options can be found here: http://paulbourke.net/dataformats/mtl/



## Setup

The glTF loader files are located [here](https://github.com/BabylonJS/Babylon.js/tree/master/dist/preview%20release/loaders).

## Full Version

This loader supports both glTF 1.0 and 2.0 and will use the correct loader based on the glTF version string.

```html
<script src="babylon.js"></script>
<script src="babylon.glTFFileLoader.js"></script>
```

## Version 2 Only

This loader supports only glTF 2.0 and will fail to load glTF 1.0.

```html
<script src="babylon.js"></script>
<script src="babylon.glTF2FileLoader.js"></script>
```

## Version 1 Only

This loader supports only glTF 1.0 and will fail to load glTF 2.0.

```html
<script src="babylon.js"></script>
<script src="babylon.glTF1FileLoader.js"></script>
```

## Loading the Scene

Use one of the static function on the `SceneLoader` to load a glTF asset.
See [Load from any file type](/divingDeeper/importers/loadingFileTypes).

See an example here: <Playground id="#WGZLGJ" title="Load a glTF Asset" description="Simple example showing how load a .glTF asset into your scene." image="/img/playgroundsAndNMEs/divingDeeperglTF1.jpg"/>

## API (Version 2)

## Properties and Methods

See the available [properties and methods](/api/classes/babylon.gltffileloader) from the API documentation.

## Extensions

See the available [extensions](/api/modules/babylon.gltf2.loader.extensions) from the API documentation.

## API (Version 1)

## Properties

### IncrementalLoading

Set this property to false to disable incremental loading which delays the loader from calling the success callback until after loading the meshes and shaders. Textures always loads asynchronously. For example, the success callback can compute the bounding information of the loaded meshes when incremental loading is disabled. Defaults to true.

```javascript
BABYLON.GLTFFileLoader.IncrementalLoading = false;
```

### HomogeneousCoordinates

Set this property to true in order to work with homogeneous coordinates, available with some converters and exporters. Defaults to false.

```javascript
BABYLON.GLTFFileLoader.HomogeneousCoordinates = true;
```

## Extensions

[KHR_binary_glTF](https://github.com/KhronosGroup/glTF/tree/master/extensions/1.0/Khronos/KHR_binary_glTF)  
[KHR_materials_common](https://github.com/KhronosGroup/glTF/tree/master/extensions/1.0/Khronos/KHR_materials_common)  


.stl File Loader Plugin