private Matrix4 createLightViewProjectionMatrix(DirectionalLight light) {
//
// -- Get the frustum corners in world space
//
mCamera.getFrustumCorners(mFrustumCorners, true);
//
// -- Get the frustum centroid
//
mFrustumCentroid.setAll(0, 0, 0);
for (int i = 0; i < 8; i++) mFrustumCentroid.add(mFrustumCorners[i]);
mFrustumCentroid.divide(8.0);
//
// --
//
BoundingBox lightBox = new BoundingBox(mFrustumCorners);
double distance = mFrustumCentroid.distanceTo(lightBox.getMin());
Vector3 lightDirection = light.getDirectionVector().clone();
lightDirection.normalize();
Vector3 lightPosition =
Vector3.subtractAndCreate(
mFrustumCentroid, Vector3.multiplyAndCreate(lightDirection, distance));
//
// --
//
mLightViewMatrix.setToLookAt(lightPosition, mFrustumCentroid, Vector3.Y);
for (int i = 0; i < 8; i++) mFrustumCorners[i].multiply(mLightViewMatrix);
BoundingBox b = new BoundingBox(mFrustumCorners);
mLightProjectionMatrix.setToOrthographic(
b.getMin().x, b.getMax().x, b.getMin().y, b.getMax().y, -b.getMax().z, -b.getMin().z);
mLightModelViewProjectionMatrix.setAll(mLightProjectionMatrix);
mLightModelViewProjectionMatrix.multiply(mLightViewMatrix);
return mLightModelViewProjectionMatrix;
}
static {
// Setup bounding box.
boundingBox = new BoundingBox(new Cube(1000, false).getGeometry());
boundingBox.setMin(new Vector3(-200, 0, -200));
boundingBox.setMax(new Vector3(200, 300, 200));
}