Read this document in the docs folder of the install.
Inside it, there is an explanation of the limb collision.
'Importing models into GameGuru.pdf'
For trees you could set collision for the trunk and have no collision for the leaves at all. Just have to find the limb number.
You will need to play with this.
For very complicated items, you may only wish to have partial collision. A Tree for example. POLYGON collision would be very slow due to the volume of the leaves and BOX collision would be too imprecise as the player would not be able to get close to the tree. For these types of items, limb collision can be used.
collisionmode = 100x
Replacing x with the limb number will cause that limb only to receive BOX collision and the rest of the object will have no collision at all. Following the above example this allows the trunk of the tree to have collision allowing the player to walk right up to it without colliding with the leaves.
See if this will allow you to shot thru the leaves.
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