RoPod/Tutorials/Load heightmap in GAZEBO: Difference between revisions
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<pre> | <pre> | ||
potrace -s | potrace -s heightmap.pgm -a 0 -r 1.016 | ||
</pre> | </pre> | ||
Then a file named heightmap.svg is created. | |||
2. Convert SVG to openSCAD file | 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 | 3. Render and create STL file | ||
4. Use STL file in GAZEBO | 4. Use STL file in GAZEBO | ||
Revision as of 14:54, 18 September 2017
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