Flat arrows

[jhurliman]

Description

With ROS arrow markers, you can set size to {1, 1, 0.01} to get a flat arrow. There doesn't seem to be any way to replicate this with SceneEntity arrows.

• Version: latest
• Platform: all

Steps To Reproduce

• Fail to make a flat SceneEntity arrow

Expected Behavior

• Succeed in making a flat SceneEntity arrow

[defunctzombie]

Are you not able to set head_length to 0? https://docs.foxglove.dev/docs/visualization/message-schemas/arrow-primitive/

What is a "flat arrow"? Like only the head?

[jhurliman]

Unfortunately, no combination of those two values will produce an arrow that looks like this (ignore the bevels):

[defunctzombie]

Is that a screenshot of the arrow you get from the ROS arrow marker or the ArrowPrimitive?

[jhurliman]

It's a random image I found online that shows a flat arrow, in the same style that the ROS arrow marker can produce. This type of style cannot be replicated with an ArrowPrimitive because you can only control head/shaft length and diameter, you can't resize per 3d axis.

[defunctzombie]

It's a random image I found online that shows a flat arrow, in the same style that the ROS arrow marker can produce. This type of style cannot be replicated with an ArrowPrimitive because you can only control head/shaft length and diameter, you can't resize per 3d axis.

Gotcha. Thanks for the additional context. I'm gonna move this to feature cause our current arrow primitive is designed for making (volumetric?) arrows rather than trying to be a 1:1 copy of the ROS Marker message.

[jhurliman]

Drawing flat arrows in 3D space is a useful viz tool. Also useful for projecting into 2D camera view