Embodiments of the invention create links or branches from a static spatial index which partitions a three-dimensional scene based on the position of static objects to a dynamic object spatial index which partitions a three-dimensional scene based on the position of dynamic objects in a three-dimensional scene. By branching from the static spatial index to the dynamic object spatial index, the image processing system may create a single combined spatial index or a combined acceleration data structure. The combined spatial index may contain information which partitions the three-dimensional scene with respect to both static objects and dynamic objects within the three-dimensional scene. When performing ray tracing, the image processing system may only need to traverse rays issued into the three-dimensional scene through the combined spatial index to determine if the ray intersects either static objects or dynamic objects within the three-dimensional scene.