i am working on a game and have some problems with the collision of the main character.
The problem is that the bounding box is way too large and i don’t have any idea how to make it smaller.
I have tried some variations in the physics options, but regardlessly what i do the character has ether a too large bounding box or i can fly trough objects without any collision.
Right now the character (the bee) has a collision box with compound activated just like the rig which is the parent of the bee. All logic bricks are applied to the rig.
I have attached two pictures where you can see the character and the bounding box.
In screen3 i switched the bounds type to convex hull.
It would be great if someone has an idea how to fix that.
thx for the reply,
yes i applied scale and rotation, unfortunately it didn`t change much.
Maybe the .blend file will help, i will post a reduced version later.
If you can make do without collision with the legs and wings then the shape of your bee looks like it could be well approximated by the “capsule” bounds shape. The “box” bounds defaults to the smallest box that your whole model can fit into, which for complex models with bits that stick out can contain a lot of empty space.
Note that bullet physics can have difficulty registering collisions with fast moving objects that are less than about 0.1 Blender units in size. Solutions for this include scaling up your entire scene, increasing the physics tick rate, or increasing the number of physics substeps. Each of these solutions can increase the processor usage in various ways and you’ll need to decide which is most appropriate for your game.
Note also that moving objects using dLoc as opposed to using forces can also lead to issues with collision for fast moving objects. If you use dLoc then you are effectively teleporting your model every frame and when moving quickly your model might teleport through the bounding boxes of other objects. By using forces or linV to move your objects you allow the physics engine to correctly interpolate the object position between frames which can increase collision accuracy.
Edit: To fully customise the size and shape of the bounding box, you can make the bee mesh “No collision” and make the bee mesh the child of an invisible physics mesh. You can size and shape this physics mesh however you want and then place the controls for your bee on this physics mesh. The visible bee mesh will then follow this physics mesh around. If the physics mesh has a very simple shape (such as an elongated box) then it might actually increase the performace of your game compared to using a complex mesh as the collision shape.
Edit2: An alternative might be to make the collision bounds of your bee mesh “sphere” and then set the bounds radius to an appropriate value.
As you can see, there are many different techniques that you can use to make the collision box perform exactly as you want it to, but not all of them are obvious. You basically need to reach a good approximation of your object’s shape that keeps performance high. I’ve not even mentioned compound collision meshes here, but that’s an advanced technique that you should move on to when you understand the basics and the performance implications.
I hope this has shed a little light on your issues.
