Shadow map plugin

This is internal plugin which adds shadow into scene.

This plugin is available in the core package.

How to use

You should initialize shadow map plugin in the AnimatedScene instance

	@Override
	protected void onStart()
	{
		ShadowMap shadowMap = new ShadowMap(getRenderer(), getScene());
	}

Configuration methods

Hard vs Soft shadows

On the image is soft shadow.

images/shadow_soft.jpg

Using the same lights, you can switch Shadow to Hard Shadows. In this case the transition from lit to shadowed regions is "hard": either something is 100% in shadow, or 100% lit. Hard shadows are faster to render but often they look less realistic.

    // By default it is true
	shadowMap.setSoft(false);
	

Shadow Cascade

Cascaded shadow maps are the best way to combat one of the most prevalent errors with shadowing: perspective aliasing.

images/shadow_hard_nocascade.jpg

Cascaded shadows work by dividing viewing area into progressively larger portions and using the same size shadow map on each. The result is that objects close to the viewer get more shadow map pixels than objects far away.

	// By default it is false
	shadowMap.setCascade(true);

Debug shadow map

For debug purpose you may want to see the field where scene objects can cast or receive shadow.

images/shadow_debug.jpg

You can enable debugging by the following method:

	// By default it is false
	shadowMap.setDebugEnabled(true);

With visible shadow camera (see below) the image will be the following:

images/shadow_debug_camera.jpg

How to Make a shadow

To make shadow you should use Directional or Spot lights.

Those classes are implementations of the abstract ShadowLight class.

Common methods

To enable shadow casting, do the following:

light.setCastShadow( true );

If you wish to cast shadow only, without lighting:

light.setOnlyShadow( true );

The following are shadow properties:

light.setShadowBias( -0.005 );
light.setShadowDarkness( 0.35 );

Also it is important to define shadow map width and height:

// By default they are 512
light.setShadowMapWidth( 1024 );
light.setShadowMapHeight( 1024 );

For debug purpose you may want to see shadow camera

images/shadow_camera.jpg

light.setShadowCameraVisible( true );

Shadow from Directional light

This light uses Orthographic camera to generate shadow.

directionalLight.setShadowCameraNear( 200 );
directionalLight.setShadowCameraFar( 1500 );

directionalLight.setShadowCameraLeft( -500 );
directionalLight.setShadowCameraRight( 500 );
directionalLight.setShadowCameraTop( 500 );
directionalLight.setShadowCameraBottom( -500 );

Shadow from Spot light

This light uses Perspective camera to generate shadow.

light.setShadowCameraNear( 200 );
light.setShadowCameraFar( 1000 );

light.setShadowCameraFov( 50 );

How to Cast and Receive shadow by objects

All objects can cast and receive shadow.

To cast shadow, just enable it in object properties:

mesh.setCastShadow(true);

To receive shadow, as well as shadow casting, do the following:

mesh.setReceiveShadow(true);