Problem loading copies of the same j3o and j3m

Troubleshooting import-assets
1

Hello, I’m hoping that somebody here may be able to shed some light on a problem with loading an exported model from the JME SDK.

With a single model, everything looks correct:


However when there’s more then one of the same same j3o and j3m only one is displayed correctly and that changes when the camera moves

Here’s the code, I don’t know if there’s something I’ve missed out, or inadvertently shared some data between the objects?

[java]
public class LoadWallTestOnlyModel extends SimpleApplication
{
private enum ResourceLocation
{
Model( “/assets/Models/WallPlaceholder/wall.j3o” ),
Material( “/assets/Models/WallPlaceholder/wall.j3m” );

/**
 * The location of the Mesh file inside the deployment JAR file (not null).
 */
private final String url;

ResourceLocation( final String relativeFile )
{
    // Make sure the file can be found - otherwise are problems!
    if (getClass().getResource( relativeFile ) == null)
    {
	throw new IllegalArgumentException( "File at the location was null - not allowed!" + relativeFile );
    }

    this.url = relativeFile;
}
}

/**
 * Rotation of one degree around the yAxis.
 */
final static Quaternion ONE_DEGREE_ROTATION = new Quaternion().fromAngleAxis( FastMath.DEG_TO_RAD, Vector3f.UNIT_Y );

public static void main( String[] args )
{
LoadWallTestOnlyModel app = new LoadWallTestOnlyModel();
app.start();
}

@Override
public void simpleInitApp()
{
// Lighting
DirectionalLight dl = new DirectionalLight();
dl.setDirection( new Vector3f( 1f, -0.6f, 0f ).normalizeLocal() );
dl.setColor( new ColorRGBA( 0.9f, 0.9f, 0.9f, 1.0f ) );
rootNode.addLight( dl );

// This update is needed to avoid assert problems due to lighting update
rootNode.updateGeometricState();

// create the geometry and attach it
final Node first = load( 0f );
rootNode.attachChild( first );

final Node second = load( -4f );
rootNode.attachChild( second );

final Node third = load( 4f );
rootNode.attachChild( third );

flyCam.setMoveSpeed( 10f );

cam.setLocation( new Vector3f( -10, 2, 0f ) );
cam.lookAt( Vector3f.ZERO, Vector3f.UNIT_Y );
}

private Node load( final float z )
{
Spatial loadedModel = getAssetManager().loadModel( ResourceLocation.Model.url );

assert loadedModel instanceof Node : "Expecting a Node object from modelFile: " + ResourceLocation.Model.url;

final Node model = (Node) loadedModel;

// Load the Material
final MaterialKey key = new MaterialKey( ResourceLocation.Material.url );
final Material material = getAssetManager().loadAsset( key );

loadedModel.setMaterial( material );
model.move( 0f, 0f, z );

return model;
}

}
[/java]

Any pointers about how to get all the copies rendering correctly would be appreciated :slight_smile:

2

The AssetManager load all ressources once.
So if you want to add severals same models, you need to clone it.

3

Cloning, eh?

Is there a special way of cloning the models, as trying the clone() method with and without cloning the material makes no difference.

[java]
// create the geometry and attach it
final Node first = load();
rootNode.attachChild( first );

// final Node second = load();
final Node second = first.clone( true );
second.move( 0f, 0f, 4f );
rootNode.attachChild( second );

// final Node third = load();
final Node third = first.clone( false );
third.move( 0f, 0f, -4f );
rootNode.attachChild( third );

[/java]

4

Solved!

The problem was no related to any caching, at least on any level I’d have control over.

This problem was being caused by the UseMaterialColors : true in the j3m file.

Setting to: UseMaterialColors : false

All the objects rendered correctly, and there was no flickering between different displays.