RoPod/Tutorials/Load heightmap in GAZEBO

From Control Systems Technology Group
Revision as of 14:54, 18 September 2017 by Clopez (talk | contribs)
Jump to navigation Jump to search

In principle Gazebo can load directly heightmaps specified in a png grayscale file. However, after following some tutorials the script did not succeed in loading a heightmap.

As an alternative, one can convert the heightmap into a 3D mesh file and load it in GAZEBO, which works straightforward. The conversion could be made in a program like blender, however here directions are given using open source software.

The conversion process is divided in several steps:

1. Convert PGM to SVG

The conversion is made using the program potrace. If not installed, run: 

sudo apt install potrace

Next, use the resolution of your heightmap to compute the corresponding dpi resolution. Use this formula:

dpi resolution = 25.4 / #mmperpixel

For the heightmap of the lab, the resolution is 25mm/pixel, thus 1.016 dpi. Next run the potrace command as follows: 

potrace -s heightmap.pgm -a 0 -r 1.016

Then a file named heightmap.svg is created.

2. Convert SVG to openSCAD file

To convert from SVG to openSCAD Inkscape needs to be installed. After installation, a plugin needs to be added to Inkscape. See step 2 on this link http://www.instructables.com/id/Make-a-3D-print-from-a-2D-drawing/



3. Render and create STL file

4. Use STL file in GAZEBO

Retrieved from "https://dsdwiki.wtb.tue.nl/index.php?title=RoPod/Tutorials/Load_heightmap_in_GAZEBO&oldid=45188"