How to add .obj model to JME

Question

For some reason I am having a hard time figuring out how to add obj models to JME. I am new to JME and have not imported models before (other than the sample assets tutorial).

I created a basic model in Blender and exported it as an obj. I added the obj to the project/assets/models folder and the mtl to the the materials folder. Unfortunately, I am still unable to see the model when I run the program. The scene appears black. I am able to see a 1x1x1 cube created in JME.

The object is a default square with another square intersecting it. Both squares have default textures.

public class TestImport extends SimpleApplication {
    public static void main(String[] args){
        TestImport app = new TestImport();
        app.start();
    }

    @Override
    public void simpleInitApp(){
        Spatial object = assetManager.loadModel(“Models/TestingOBJ/TestingOBJ.obj”);
        rootNode.attachChild(object);
        DirectionalLight sun = new DirectionalLight();
        sun.setDirection(new Vector3f(-2f,-2f,-2f).normalizeLocal());
        rootNode.addLight(sun);
    }
}

Help please!

Answer 1

Textures are not exported in .obj files, and therefore you are trying to view an untextured asset within JME. Try adding a Material to the object after using the asset manager to load the model.

public class TestImport extends SimpleApplication {
    public static void main(String[] args){
        TestImport app = new TestImport();
        app.start();
    }

    @Override
    public void simpleInitApp(){
        Spatial object = assetManager.loadModel(“Models/TestingOBJ/TestingOBJ.obj”);
        Material mat_default = new Material(assetManager, "Common/MatDefs/Misc/Unshaded.j3md");
        object.setMaterial(mat_default);
        DirectionalLight sun = new DirectionalLight();
        sun.setDirection(new Vector3f(-2f,-2f,-2f).normalizeLocal());
        rootNode.addLight(sun);
    }
}

So that JME knows where to find them, ensure that you have placed your assets in the assets/Textures/ folder.