Creating a height map from point cloud for 3d map making

[Darce]

I'm interested in creating height maps for 3d modeling. I've been learning to make Photoshop grey-scale clouds to make my own height maps. I also found a number of height maps on line. What I would like to do is create my own library of height maps of real world locations to edit into my unique map art. This will allow me to just paint in a river or valley, etc. I wish to find others who have experience creating height maps, or a tutorial I may have missed on You Tube.

[Redrobes]

Your height maps sounds like grey scale raster bitmaps and not point clouds. If you do really mean point clouds then the word you are looking for is "Delaunay".

If you have bitmaps then create a greyscale mask bitmap from black where you want the old bitmap and white where you want the new one. Clip bits out of the real world bitmap and align on a new bitmap where they need to be placed. Take your old map and ensure that its ok to lose all the height map where your masking in the new one.

Ensure that the borders of the splats in the mask fade down nicely from white to black using gaussian blur or similar.

Then multiply the new real world bitmap with the mask and call that image A.
Invert the mask.
Multiply inverted mask with old terrain and call that image B
Then add A + B for new terrain.

Your doing all of this in 8bits per pixel I expect. You will have jaggies on the height or height banding appearing. You can do all of this in 16bpp greyscale too or use something better like a floating point map with some other software. But the masking will work on all bitmap apps that do multiply and add processes.

Edit: Also note that whilst this will give you what you asked for it doesnt necessarily provide proper geomorphology or "sensible" terrain. To do that is very hard indeed - perhaps impossible. Some apps can get closer than you can do with a mask tho. See world machine, geocontrol, etc and wilbur to some extent but has that nicely 'free' ring to it.

[johnvanvliet]

the GPL'ed and free software Blender is what i use for 3d work

and i do a LOT of work with DEM's and "height maps"

your question reminds me of a post i responded to last night over on Blender Artists

post 4 and 5
http://blenderartists.org/forum/show...ort-to-Blender

a GRIDDED!!!! ( that is important !!! ) height data set is basically a 16 bit or 32 bit float image ( i use tiff for these )
a NON-GRIDDED!!! like from a laser scanner or LIDAR detector wold be a 3d set of POINTS -- a "point cloud"

for point clouds you need to GRID THEM !! or mesh them

for direct converting to a mesh use "meshlab" - - you might need to build the source code
http://meshlab.sourceforge.net/
or
install gdal and use the terminal
to use gdal's tools "gdal_grid" to convert a non gridded data set to a gridded data set
( a lot of work sometimes )
for an example see:
http://www.spatialguru.com/gdal-rast...or-ascii-data/

this can also be done using Qgis
see:
http://hydrogeotools.blogspot.com/20...-xyz-data.html