Fig. 8: Empty-space skipping for multiple channels.

Traversal starts at the root node and the first channel. The node is non-empty, so we proceed to the next subdivision level (1). For the first channel, this node is empty, so we can stop traversing the tree for this level and proceed to the next channel (2). The node is non-empty for channel 2, so we proceed to the next subdivision level (3). We repeat this procedure until we finally can skip the largest node in which all channels are empty (5).