The RasterDEMGenerator currently includes 2 inputs:
- Points/Lines
- Breaklines.
I find I almost always follow this with a Clipper to clip the DEM to the shape of my input data - typically terrestrial LiDAR along a road or rail corridor; using a polygon (hull) to remove unwanted interpolated cells. As the RasterDEMGenerator is interpolating all those cells outside the pointcloud it is very taxing on performance. A built-in clipper or another way of tiling the DEM generation process would vastly improve performance.