bool AABBTree::buildInit(AABBTreeBuildParams& params, BuildStats& stats)

{

	// Checkings

	const PxU32 nbPrimitives = params.mNbPrimitives;

	if(!nbPrimitives)

		return false;

	// Release previous tree

	release();

	// Init stats

	stats.setCount(1);

	// Initialize indices. This list will be modified during build.

	mNbIndices = nbPrimitives;

	mIndices = reinterpret_cast<PxU32*>(PX_ALLOC(sizeof(PxU32)*nbPrimitives, "AABB tree indices"));

	// Identity permutation

	for(PxU32 i=0;i<nbPrimitives;i++)

		mIndices[i] = i;

	// Allocate a pool of nodes

	mNodeAllocator.init(nbPrimitives, params.mLimit);

	// Compute box centers only once and cache them

	params.mCache = reinterpret_cast<PxVec3*>(PX_ALLOC(sizeof(PxVec3)*(nbPrimitives+1), "cache"));

	const float half = 0.5f;

	const FloatV halfV = FLoad(half);

	for(PxU32 i=0;i<nbPrimitives;i++)

	{

		const Vec4V curMinV = V4LoadU(&params.mAABBArray[i].minimum.x);

		const Vec4V curMaxV = V4LoadU(&params.mAABBArray[i].maximum.x);

		const Vec4V centerV = V4Scale(V4Add(curMaxV, curMinV), halfV);

		V4StoreU(centerV, &params.mCache[i].x);

	}

	return true;

}