How to Transform tf::Transform to btTransform

asked 2015-10-13 01:04:49 -0500

johnny.lin
5 ●4 ●4 ●6

    void broadcastKinectTransform(const tf::Transform& transform, const std::string& kinect_rgb_optical, const std::string& ground, tf::TransformBroadcaster& broadcaster, const tf::TransformListener& listener) {
    std::string link;
    if (listener.getParent(kinect_rgb_optical, ros::Time(0), link) && listener.getParent(link, ros::Time(0), link)) {
            tf::StampedTransform tfTransform;
            listener.lookupTransform (link, kinect_rgb_optical, ros::Time(0), tfTransform);
            broadcaster.sendTransform(tf::StampedTransform(transform * tfTransform.asBt().inverse(), ros::Time::now(), ground, link));
    } else {
            broadcaster.sendTransform(tf::StampedTransform(transform, ros::Time::now(), ground, kinect_rgb_optical));
    }
}

In the above function, .asBt() is deprecated, what should I do to finish the transformation?

answered 2015-10-13 16:30:23 -0500

Boris

3060 ●32 ●57 ●83 http://people.idsia.ch/~gromov

updated 2015-10-14 07:54:47 -0500

You can simply remove the .asBt() part. Multiplication of tf::StampedTransform by tf::Transform will return tf::Transform.

EDIT

Both Bullet and tf have almost identical interfaces, but the type names differ. So you have to convert everything using POD-types, for example floats array.

To convert btTransform to tf::Transform do something like this:

btTransform bt_transform;
tf::Transform tf_transform;
float gl_matrix[15];

bt_transform.getOpenGLMatrix(gl_matrix);
tf_transform.setFromOpenGLMatrix(gl_matrix);

Or you can do this component-wise by separately extracting quaternion and origin vector from Bullet transform and setting them back to tf transform. But I think the above method is cleaner.