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plc/PassThrough: Unable to lookup, cache is empty?

asked 2012-08-03 03:13:58 -0500

liborw

801 ●47 ●57 ●67

Hi,

I have a problem converting a point cloud form one frame to another using plc/PassThrough filter. The problem, it seems, is that the PassThrough filter is too fast for lookup cache to fill. How can I make the filter to wait awhile for the cache to fill?

Thanks

The error message is:

[ERROR] [1343999032.826366155]: Unable to lookup transform, cache is empty, when looking up     transform from frame [/camera_depth_optical_frame] to frame [/base_link]
[ERROR] [1343999032.826482353]: [/cloud_to_baselink::computePublish] Error converting output dataset from /camera_depth_optical_frame to base_link.

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answered 2012-10-21 12:26:49 -0500

tfoote

58457 ●128 ●550 ●526 http://www.ros.org/

Do you construct your TransformListener before the call and does it persist to allow it to build up it's cache? If so, do you also probably need to be robust to the cache not being full the first time, and need to let it retry for a couple cycles to let the cache fill up.

You might also want to look at using a tf::MessageFilter to hold data until transforms are available.

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Asked: 2012-08-03 03:13:58 -0500

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Last updated: Oct 21 '12

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