# Revision history [back]

### tf fixed transforms with timestamps

Hello ROS users,

I'm slightly confused about how TF handles transforms.

I'm using the tf::TransformBroadcaster class in a node called tf_broadcaster_node for publishing transforms to TF, resulting in the following TF tree:

These frames have fixed transforms (only rotations), represented below as RPY(in degrees) :

• base_link --> camera_frame : Rotation (50, 0, -90)

• camera_frame --> bundler_camera_frame : Rotation is (0, 180, 0)

I also have a tf_listener_node which is used to query and print these transforms from TF. My expectation was that the fixed-value transforms will be printed exactly as defined above. However, I was surprised to note that they were different:

Question : Why do the fixed transform values differ from their definitions?

I'd appreciate any assistance in helping me understand TF better. Thanks!

### tf fixed transforms with timestamps

Hello ROS users,

I'm slightly confused about how TF handles transforms.

I'm using the tf::TransformBroadcaster class in a node called tf_broadcaster_node for publishing transforms to TF, resulting in the following TF tree:

These frames have fixed transforms (only rotations), represented below as RPY(in degrees) :

• base_link --> camera_frame : Rotation (50, 0, -90)

• camera_frame --> bundler_camera_frame : Rotation is (0, 180, 0)

I also have a tf_listener_node which is used to query and print these transforms from TF. My expectation was that the fixed-value transforms will be printed exactly as defined above. However, I was surprised to note that they were different:

Question : Why do the fixed transform values differ from their definitions?

I'd appreciate any assistance in helping me understand TF better. Thanks!

### tf fixed transforms with timestampstransforms

Hello ROS users,

I'm slightly confused about how TF handles transforms.

I'm using the tf::TransformBroadcaster class in a node called tf_broadcaster_node for publishing transforms to TF, resulting in the following TF tree:

These frames have fixed transforms (only rotations), represented below as RPY(in degrees) :

• base_link --> camera_frame : Rotation (50, (-90, 0, -90)50)

• camera_frame --> bundler_camera_frame : Rotation is (0, 180, 0)

I also have a tf_listener_node which is used to query and print these transforms from TF. My expectation was that the fixed-value transforms will be printed exactly as defined above. However, I was surprised to note that they were different:

Question : Why do the fixed transform values differ from their definitions?

I'd appreciate any assistance in helping me understand TF better. Thanks!