How should I create a Pawn which has gravity, simulates box collision physics, and can be moved by a player/AI?

[galact1c]

I’m quite new to Unreal Engine, so sorry if I have made any obvious mistakes.

TLDR: Pawn with FloatingPawnMovement which has box collision and physics is getting stuck on the ground. Character does not seem to be appropriate for what I am creating. Movement components are necessary for AI movement from my understanding. I’m unsure what the correct approach is.

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I want to create a simple non-wheeled vehicle with box collision. From my understanding, making this using Character would force me to use capsule collision. It also wouldn’t make sense as this is not a human-like vertically-oriented player.

My current setup is a Pawn with FloatingPawnMovement which has collision enabled with the Pawn preset, and Simulate Physics enabled. Everything works perfectly, however, once the box collision bounces a few times and settles on the ground (whether BSP or static mesh), it gets stuck.

Screenshot 1: Current setup. Root is a box collision component.

Screenshot 2: Movement setup with FloatingPawnMovement.

• Once stuck, no amount of movement speed is able to move the Pawn. I’ve tried setting extremely high values with no success.

• Using Sphere and Capsule collision do not produce these results (I presume this is because these collision shapes touch the ground at one point).

• Using AddActorLocalOffset does work, if Sweep is not enabled. (This might be where the movement is failing). However, I want to be using a movement component. From my understanding, this is necessary for AI movement. Using physics velocities seems like the incorrect solution.

• Setting velocity using SetPhysicsLinearVelocity does work however I’m unsure how good of an idea it is to use this for player movement. Again, I’m pretty sure that using a movement component is needed for AI.

• My first thought was that friction was possibly preventing movement. However using the Physical Material attached below didn’t have any effect.

• Interestingly, if using an actor with box collision as the ground rather than BSP or a static mesh, the Pawn does not get stuck and moves as expected.

Screenshot 3: Frictionless Physical Material.

I would like to simulate physics because I need the vehicle to have gravity and to rotate correctly when driving up a ramp, etc.

Although I have posted this in Blueprint Scripting, if C++ programing is necessary, I can work with that too. All suggestions are welcome.

[Everynone]

Nicely put. +10 Internet Points for the concise and informative description.

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Things I’d definitely try out:

• CCD on the simulated root

• up the solvers:

• make a chamfered mesh the root (instead of the box collision), open it in the editor, remove collision and add 18DOP:

This will result in a nicely bevelled simplified (green lines) collision that does not snag. fingers crossed

Do tell if any of this helps at all!

[galact1c]

Thank you so much for the help!

Enabling Use CCD and increasing the solver iteration count unfortunately didn’t fix the issue. I played around with the value and decreasing the position solver iteration count actually caused it to get stuck and unstuck likely because of the collision inaccuracy.

However, I did try the chamfered mesh idea, and it worked! Interestingly, this also worked with the default cube static mesh. The bevels aren’t visible but the pawn no longer gets stuck to the ground.

Screenshot: Default cube with 18DOF Simplified Collision (bevel is invisible?)

Using auto convex collision for a beveled mesh also ended up also working.

I imagine a solution using box collision could be better as that has less geometry, or maybe I’m overthinking it.

[Everynone]

Awesome, thanks for the update!

[americo84]

I have a similar problem but still I am not able to solve

When the enemy character is spawned in air or is moved floats
If i enable simulate physics falls under the landscape

Please please please help me

Best reguards