1. A computer-implemented method for iterative Monte Carlo volume rendering, the method comprising: tracing, by a computer processor, a plurality of light rays into a scene containing volumetric data, the light rays configured for simulating global illumination; randomizing, by a computer processor, a scattering location and a scattering direction of the plurality of light rays through the volume, wherein a common sequence of random numbers is used in order for the scattering direction of each of the plurality of randomized light rays to be substantially parallel; computing, by the computer processor, at least one trilinearly interpolated and shaded sample along each of the plurality of randomized light rays based on stored volumetric data, wherein at least a portion of the stored volumetric data used in at least a portion of the computing is configured for coherent memory access; rendering, by the computer processor, the volume with the global illumination based on a plurality of iterations of the tracing, the randomizing, and the computing.