I am using the RasterDEMGenerator transformer to create a digital elevation model. The resulting raster cells cover the entire bounding box of my point cloud. So far so good.
What I want to achieve is, that such raster cells, that do not cover any point of the point cloud will have a "NoData" value. I have tried all of the available interpolation methods, but non eof them seemed to work in this respect.
Any ideas? Thank you
You probably want to use the NumericRasterizer to create a raster from pointcloud.
Hi Niels,
thanks a lot. Now "NoData" values are created correctly where raster cells do not cover points.
However, it seems like there is no way to control from which of those points that are covered by a single raster cell the value is adopted. I attached 2 images:
Image 1 -The highlighted raster cell covers 4 points: 21.98, 20.01, 23.04, 21.56. The respective raster cell value is 20.01.
Image 2 - The highlighted raster cell covers 4 points: 10.08, 20.85, 24.80, 20.08. The respective raster cell value is 20.85.
Seems like it is alway adopting the value from the top-right point. I would like to always pick the smallest value.
Any ideas?
forgot the images
Hi Niels,
thanks a lot. Now "NoData" values are created correctly where raster cells do not cover points.
However, it seems like there is no way to control from which of those points that are covered by a single raster cell the value is adopted. I attached 2 images:
Image 1 -The highlighted raster cell covers 4 points: 21.98, 20.01, 23.04, 21.56. The respective raster cell value is 20.01.
Image 2 - The highlighted raster cell covers 4 points: 10.08, 20.85, 24.80, 20.08. The respective raster cell value is 20.85.
Seems like it is alway adopting the value from the top-right point. I would like to always pick the smallest value.
Any ideas?
I'm by no means an expert on raster so this probably can be accomplished easier. But if you are happy with the RasterDEMGenerator's output, I think you can add the NumericRasterizer's output nulls to it using the RasterExpressionEvaluator. You then have the interpolated raster and the not interpolated null values.
I'm by no means an expert on raster so this probably can be accomplished easier. But if you are happy with the RasterDEMGenerator's output, I think you can add the NumericRasterizer's output nulls to it using the RasterExpressionEvaluator. You then have the interpolated raster and the not interpolated null values.
Thanks- this may work. I will give it a try.
Hi @friedhelm,
I think you should add a PointcloudSorter before the NumericRasterizer. If you sort Z (descending), the resulting raster should have take the lowest z-value for the output raster.