Hi Everyone, I've downloaded a "dem" file from the USGS website and would like to smooth out or overwrite certain areas. In the attached image, there is a hill area outlined in red in which the top of the hill suddenly caves in on itself. The area I've circled in blue is actually a freeway that runs across the landscape. Can anyone suggest ways to eliminate unwanted detail from a DEM? I've loaded the actual source file via the Geog Heightfield Loader node and the raw data is a .img file. Thanks for your suggestions.
One way would be to use world machine to blur out detail with masks. Another would be to set an orthographic camera looking down on the dem in TG, checking shade by height in the HF node, so that you can export a greyscale image you can then take into a paint package and blur unwanted areas, then re-import as an image to displace.
You might try using a Painted Shader to paint in additional displacement there (or paint out the heightfield). For the former, you would just add a Displacement Shader with the Painted Shader as input; for the latter, you would add the Painted Shader as a mask for the Heightfield Shader. If you paint out the heightfield, you'll end up with a hole there which you would then want to fill with procedural data, or perhaps flat; you could do this by using the Painted Shader output as the Mask input for a Power Fractal, but inverted so the Power Fractal *only* displaces where the Heightfield is masked out. Then you would adjust Displacement Offset and Amplitude to get the effect you want. I'm not certain how well this will work, but may be worth experimenting with.
- Oshyan