The amount of diffusion (or length of the kernel) given in voxel size. Be careful with high values. Higher values take longer to calculate.

The diffusion process can be looped by setting a higher iteration count. Takes linearly more time per iteration.

Defines the diffusion intensity per iteration. You can use the spline graph to control the intensity.

Example:
If you have 3 iterations, then the center of the spline graph's x-axis defines the value for the 2nd iteration, the right the 3rd and the left side the 1st iteration.