Revision history [back]

The transforms are stored in a tree, every frame can have at most one parent. Thus when you publish a new transform like that you are effectively reattaching the transform to the other branch of the tree. If you want to connect to disconnected trees you have to connect them at the root.

If you have something like an ar tag. You can compute the transform from camera_lin to ar_marker0 Tca through the camera. Then if you know the transfrom from the world to the ar_marker0 (Twa) you publsh the transform from world to camera_link (Twc) as the as known transform minus the computed transform. Twc = Twa - Tca This is just Twc + Tca == Twa solving for Twc which is the missing link in your tree.

The transforms are stored in a tree, every frame can have at most one parent. Thus when you publish a new transform like that you are effectively reattaching the transform to the other branch of the tree. If you want to connect to disconnected trees you have to connect them at the root.

If you have something like an ar tag. You can compute the transform from camera_lincamera_link to ar_marker0 Tca through the camera. Then if you know the transfrom from the world to the ar_marker0 (Twa) you publsh the transform from world to camera_link (Twc) as the as known transform minus the computed transform. Twc = Twa - Tca This is just Twc + Tca == Twa solving for Twc which is the missing link in your tree.

The transforms are stored in a tree, every frame can have at most one parent. Thus when you publish a new transform like that you are effectively reattaching the transform to the other branch of the tree. If you want to connect to two disconnected trees you have to connect them at the root.

If you have something like an ar tag. You can compute the transform from camera_link to ar_marker0 Tca through the camera. Then if you know the transfrom from the world to the ar_marker0 (Twa) you publsh the transform from world to camera_link (Twc) as the as known transform minus the computed transform. Twc = Twa - Tca This is just Twc + Tca == Twa solving for Twc which is the missing link in your tree.