Collada (.dae) meshes with unit != "meter" broken?

asked 2015-02-16 05:27:58 -0600

andreasBihlmaier
56 ●1 ●2 ●4

updated 2015-02-16 05:49:17 -0600

Dear community,

I'm having trouble with URDFs that used to work since Hydro. If they contain a collada (.dae) mesh which has <unit> with non meter units (e.g. centimeter):

--- collada_unit_meter.dae      2015-02-16 11:14:28.128423513 +0100
+++ collada_unit_centimeter.dae 2015-02-16 11:16:06.542388857 +0100
@@ -7,7 +7,7 @@
     </contributor>
     <created>2015-02-16T11:14:28</created>
     <modified>2015-02-16T11:14:28</modified>
-    <unit name="meter" meter="1"/>
+    <unit name="centimeter" meter="0.01"/>
     <up_axis>Z_UP</up_axis>
   </asset>
   <library_images/>
@@ -97,4 +97,4 @@
   <scene>
     <instance_visual_scene url="#Scene"/>
   </scene>
-</COLLADA>
\ No newline at end of file
+</COLLADA>

no mesh at all is displayed in rviz RobotModel. It seems the mesh is also ignored for MoveIt! collision checking.

Test files can be created by simply exporting the default cube as .dae in Blender. Once without modification and once with modified . These files can also be found here: https://gist.github.com/andreasBihlma...

Can anybody confirm this issue?

Regards, ahb

Addition: The same meshes (with unit != meter) worked fine and continue to work fine with gazebo. Actually, I convert the .sdf to .urdf using pysdf.

answered 2015-02-16 05:41:58 -0600

Stefan Kohlbrecher

24361 ●173 ●299 ●444 https://www.energy-rob...

updated 2015-02-16 05:45:14 -0600

Sounds like a regression to me, you should probably file a bug ticket for rviz. The fact that things ceased working also for moveit suggests a broader issue with how mesh loading works, however. Hopefully, a issue on rviz will trigger the necessary discussion of this.

While I can't confirm your issue directly, I also noticed changes in COLLADA handling between hydro and indigo. I encountered another issue where rendering didn't work in hydro, but did so in indigo (see drcsim Bitbucket #466).

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Comments

I was not sure where to file the bug (rviz, urdfdom, ...), thus I wanted to ask here before.

andreasBihlmaier ( 2015-02-16 05:47:47 -0600 )edit

I can confirm this issue. Meshes get loaded fine without any error message, but nothing is displayed. Re-exporting such that the unit is meter seems to be the only remedy. These are meshes that worked fine in rviz hydro.