Scan output still contains inf even when use_inf is false

[hughcorley]

Data on the scan topic still contains inf data points even when use_inf is false. To remedy this, range_max must be set to something, and use_inf must be false. In other words, the default value of range_max does not seem to affect the infinite range (defined as range_max + 1 if use_inf is false). Instead, range_max must explicitly be given a value in order for the infinite range to be range_max + 1.

[paulbovbel]

range_max is double max by default (https://github.com/ros-perception/pointcloud_to_laserscan/blob/lunar-devel/src/pointcloud_to_laserscan_nodelet.cpp#L70). Where do you see it translated into inf?

[hughcorley]

Sorry maybe I wasn't clear. I don't mean to say range_max is ever inf. What I mean to say is that setting use_inf to false does not work unless you also explicitly set range_max to something. Does that make sense?

[paulbovbel]

I wasn't clear either :)

range_max drives a few behaviours:

• it's the default value of any ray when !use_inf
• any trace larger than range_max is ignored

So if !use_inf, and you're seeing inf reported in the laserscan, then it must be driven by range_max. Can you provide your launch file?

[hughcorley]

Not to worry :)

Right, so I set !use_inf and if I do not explicitly set range_max (i.e. I let it use its default value) then I see inf in the data. In other words, the following launch code results in data which is upper bounded by some finite value

    <node pkg="pointcloud_to_laserscan" type="pointcloud_to_laserscan_node" name="pointcloud_to_laserscan">
      <remap from="cloud_in" to="velodyne_points"/>
      <param name="use_inf" value="false"/>
      <param name="range_max" value="200"/>
    </node>

while this does not

    <node pkg="pointcloud_to_laserscan" type="pointcloud_to_laserscan_node" name="pointcloud_to_laserscan">
      <remap from="cloud_in" to="velodyne_points"/>
      <param name="use_inf" value="false"/>
    </node>

That make sense?

Thank you for the prompt replies! Hope you stay well during this time.