Setup: I destroy my wall using a field. I want to then enter the building through the hole in the wall, but when I step on the bricks that have scattered around as a result of the fracture, two things happen;
The fractured pieces fly around under foot.
My character spins and the camera goes crazy as it steps on the bricks.
Things I have tried.
I have set a sleep field across the floor and tested the following settings in it’s field behaviour settings:
Sleep - result: objects wake up upon collision - same issue
Disable - result: collision is fully disabled so character phases through rubble instead of walking on top.
Kill - result: collision fully disabled.
(I should add that I am not looking to shrink and remove the fracture pieces so that setting is of no use)
My Geometry Collection is set to Implicit-Implicit Convex. I have tried all the other settings in both Implicit-Implicit and Particle-Implicit.
The best result I can get so far is Particle Implicit Level Set, which tanks frames on fracture, so I don’t want to use that setting - but that is also not what I am looking as the debris still moves when you walk into it, it just no longer sends the camera crazy.
Implicit-Implicit Level Set instantly crashed UE5.4.4 as soon as I enter PIE. so can’t tell if that works.
All I want is to be able to set the debris to a state whereby I can walk on it without moving it.
Any help would be great.
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Did you ever find a solution? I am working on the same problem right now as I start working with destruction.
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It can be also set from the geometry collection’s details panel. You can simply remove collisions after crumble at some level.
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Not looking to disable collision, but rather have the pieces be able to be physically walked on (or bumped against depending on size) without the pieces moving and causing crazy things to happen to the player because of the pieces moving, rotating, etc which freaks the player capsule out, spinning it around, sometimes shooting it off in random directions.
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I understand, are you using sleep/disable field?
Cause when I use, I can walk?
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I would like to know how to set that up as well as how to set it up while having gravity disabled. 2 different issues for me heh. Sounds like sleep/disable might work when gravity is enabled which is good news, I’ll give that a shot.
Here’s my other use case with gravity disabled. Haven’t found a way to get the pieces to have one way collision (player affects pieces, but pieces do not affect player). Any idea how to make that work? Here’s a demo video of the mess it causes with them both colliding.
Well ok understood now what you mean, its a much more harder question become instantly with no gravity. First thing to check to walk around the problem maybe handling player can step on or not, on a surface check. We can just reject to step up maybe preventing this tornado turns.
allright so I was playing this for a while and found out that there is a slope control on GC.
Where you can set the collection to “Can Character Step Up” to No and
you can effect the walkable slope on this so it always pushes player back on ground.
Besides I created a new material and set the collection density lower so that the debris overall mass per instance become lower, default 1gr/cm3 is kinda high ( depends on the volume ofc) so the debris inertia effects on character becomes well less noticable on impact or the moment goes down under capsule.
I used just a sleep disable field and used a sleep on it. This also allowed my character to push down the debris under feet to ground and go sleep after loosing inertia.
Also in physics material I made sure on field applied, lower tensile so it can break easy (just for caution)
This give me quite nice results on a setup like this.
and result is
its not perfect however its a partial solution I think, can you try?
After this ofcourse becomes unwalkable however after they sleep we can apply walkable again and keep them in place. Especially the ones close to walking surface so it doesn’t effect player from traversing and keep actual collisions.
Made some tests with some tiny geometry with same setup, it works.
A Test with no gravity gc
A Test with no gravity gc, only sleep applied for not moving (5), constantly jumping on debris
Gameplay wise if there is going to be in the hallway pathway etc. OnSleep on pathway physics sim can be disabled for a nicer traversal still depending on the geometry a movement component modification or camera modification can be required for a smooth experience.
A test with one GC gravity enabled, other not, after delay debris have no simulation.
as example below I just disable after delay no gameplay logic of correct placement or sleep.
Not perfect but imo acceptable.
Wow this looks great! Sorry for the delayed response I haven’t been on the computer all week, but wanted to follow up real quick to acknowledge how good it looks compared to default. I can’t wait to try sorting through everything you have shown and posted and try it myself. I unfortunately have homework for another class that will take up my day today, but hopefully I will get to try this soon! Thank you! And I will update when I have a chance to dive in!
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Sorry for the delay, I was sick last week and unable to get on the computer. This worked great! I do still need to play more with the inertial and mass values to get it a bit more how I like it, but you solved 2 weeks of headache and endless web searching for me. I had tried using the one way before but failed to change the group number, so that was the key to making it work properly.
Also do you have any idea why my bullets don’t collide with the mesh surface facing my character when I start? It goes through and collides with the back face. If I rotate the mesh 180 degrees in the level editor it does the same, the bullets travel through the surface facing the player, but if I walk around back (like in the video) it collides and creates the particles on the outside surface of the mesh. Bullets react fine to other meshes, only doing this behavior against the geometry collection.
I would love to connect with you and chat sometime if you maybe have discord or similar, as I haven’t found many people who know anything more about destruction than what you can find in the base youtube tutorials. Appreciate the help!
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Hi glad that it worked, we can talk anytime here or somehwere else, dm me for discord.
My knowledge on chaos also similar, maybe its easier for me to understand what is going on since I am familiar with theoretical physics, not sure.
In terms of collision problem you mentioned, it would be better to go slomo 0.1 command, eject from player and alt+c to display collision are reacting where it should be. So that you confirm that collisions of weapon, projectile and geaometry collection are right. After that if issue still persists we can look some other places like simulation time steps and ticks.
