PhysX Lab to UE4 collision problems

Hello!
I am trying to create a destructible asset using PhysX lab and using it in UE4. However after I export as .apb and import mesh, when I play and shoot mesh, it explodes randomly. This is not issue however, issue is that collision of each chunk is not perfect, UE4 has sort of made a box around each chunk and not any details. This is why I think chunks are standing on its sides and having weird physics. Note I am using FPS example on a new level. I used a fracture map to fracture my texture in PhysX Lab. I am using UE4 4.2, im not sure if updating to 4.3 will help but it might, let me know! Im also not sure if it is part of my settings that is ruining this, or it is a bug. I have tried turning up global gravity but chunks just drop when shot, all at once and it doesnt fix collision either. Also note,I have tried most methods found on answer hub to resolve this, nothing worked (changed impactdepth, various blueprints, etc.). I also have noticed that when i select a chunk in destructible editor (preview depth 1) it is a box around it, not conformed around chunk, outline that is. I hope this get resolved soon, thanks in advance!

I’m having same collision problem. chunks have collision boxes that are too large. So they end up floating above ground.

Hey,

box that surrounds your chunk in Destructible editor is not its collision. I’m not sure why you have chunks sitting oddly. Would you mind linking me to a test asset with which this happens so I can see if there’s a bug? Thanks!

Yeah I can send you object when I get home, it is in an .apb file format. Thanks

Also, it happens with all assets that I transfer from PhysX Lab so ill just send you any one. Not sure why this is though!

following link is for anyone who wants to see what i’m talking about, just load FPS game and put this in your scene and shoot it!

Thanks for test asset. I’m seeing same thing when I import it into my project, but creating a new destructible asset in PhysX Lab does not reproduce this behavior. I’m inclined to believe there’s a setting in your PhysX project that is exporting the .apb with some unusual values. Would you mind creating a project that creates destructibles with this behavior and then putting that up somewhere for me? Thanks!

For some reason when i save project and open it again, it opens with nothing in it. I’ll just take screen shots of all settings and post them up

Ok i have pre fracture settings, post fracture will be up soon!

Oh and theyre not in order! Sorry!

Actually there is no need for post fracture, i didnt change any settings, but let me know if you need it!

Also, i’m using fracture map included with physx lab with a simple box mad in maya exported as obj

I may have fixed collision issue however, three more have arisen. But I think I fixed collision by making collision shape, collision decomposition in PhysX lab. And that fixed issue where they would float and have random defying physics properties. But now I have an issue where DM spawns about a foot off ground no matter how deep I place it in scene (I am trying to make it flat on ground). And also when destructible mesh is shot, all chunks explode only on Y and Z axis, and when all chunks land, most of them are standing on their edges up on Y axis. Which brings me to my next problem which is that every chunk is being destroyed instantly as object is shot, even when I select world overlap and impact damage in PhysX lab (I also put defaultimpactdamage to 1 and it didnt fix it). I’m pretty sure collision is fixed because when I walk over chunk it gets pushed and falls flat on ground and can be pushed even more (however not all of them are interactable with?). They also collide with each other properly. I think collision shapes get clipped through each other when DM is destroyed, cause when I walk over them, their collisions are fixed (chunks that are interactale anyway)! There is also quite a bit of lag when DM is shot (probably cause so many chunks are being generated) so thats why I want impact damage, world support and support chunks! So if you can find a fix for this, it would be great! Heres a couple of screenshots! DM chunk error - Album on Imgur

I’ve tried creating a new DM with settings you have displayed and it is not behaving way yours does. There are a couple of possibilities here: most likely, either your mesh itself is being exported from Maya incorrectly or you have some mixture of settings in PhysX Lab that I’m not seeing that is causing this. I’ve messed around in PhysX for a while and wasn’t able to come up with anything that would do this, so my guess is that it has something to do with your export process from Maya.

asset you attached earlier needed to be scaled up significantly for me to test it properly, and scaling it caused some very unusual behavior. I’m wondering if this happens for you as well? If you create your mesh using centimeters as base unit in Maya, and export it as an FBX, do same problems occur?

Otherwise I’m not certain what could be causing this. If you’d like, you can send me a test mesh and I can attempt same process in PhysX Lab so we can maybe narrow it down to that as root of problem. If you do, please send it exactly way you have when you import it into PhysX. Thanks!

Ok so I scaled it out directly from maya then exported to PhysX Lab and fractured it using same settings. I imported it to UE4 and it seems to be working in FPS template, however some pieces dont break no matter how much damage I apply with gun or damage threshold is significantly higher than rest of chunks. collision is fixed and seems to fall normally. I tried to shoot it in FPS game and mesh just disappeared, I only had time to try once before I had to go, but i’ll try again tonight. Thanks for all help, one last issue before this dilemma is resolved.

Yeah so DM for some reason just disappears when I shoot it in FPS sample, i’m not sure if it is just flying away REALLY fast or it just straight up disappearing. However scaling it up fixed almost everything in FPS template, only problem is that it can take damage on first hit, and explodes normally, then after I try to shoot remaining chunks, after a few shots second chunk breaks then no more. No matter how much I spam, after second chunk breaks off, no more can be broken off. I have also found that if I break chunks in a specific order that can work sometimes, but not always. Thanks so much again and I hope you can resolve this asap!