Collision Prevention
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Do you recall that we mentioned **Vision** does not able to detect box/basket like boundary? It is simply because the camera is capturing from 
one side and the wall/edges of the box is merely a line in the scene. Computer is not human, they don't know that edges is obstacle for them. 

.. image:: Images/box_detector.png
    :align: center

Therefore, you will need to tell the robot where this obstacle and warn it to avoid the collision. 

**Collision Avoidance** node is born to deal with this problem. 

.. image:: Images/collision_avoidance.png
    :align: center

It takes the **Object in Cloud** (from detection) relation and **Object in Tool** relation(Pose Define **Gripper** node) as inputs. 
You can see there is a **Bin Setting** in this node, which is the obstacle you set for the robot. 

.. image:: Images/bin_setting.png
    :align: center

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In this Virtual bin setting, you can define the box-obstacle for the robot arm. Any pick poses collide with this obstacle, **Collision Avoidance** node will filter out these poses, 
Only keep the ones which are collision-free. You can use the coordinate values to setup the box or even simpler, drag the box in scene. 

.. image:: Images/virtual_box.png
    :align: center

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You will see the visualization effect of these collision-free pick poses like below:

.. image:: Images/collision-free_pose.png
    :align: center

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