Does this software mainly use my CPU or GPU?

[IBDPool]

if the answer is CPU, is there a way to make the software use my Nvidia GPU to maybe speed up the process?

[ARitz-Cracker]

Skimming through the source code, while it does use the GPU for some things, the main algorithm to create the animation is CPU-only. Unsure how parallelized this algorithm can be, it first glance it doesn't seem like the thing of thing that's appropriate to run on the GPU but I could be wrong.