# Unwanted rotations of collision primitives from Blender. **URL:** \ **Category:** Pipeline & Plugins\ **Tags:** Blender, fbx-export, ImportExport, unreal-engine, Collision, issue, question\ **Created:** [February 14, 2025, 6:36pm UTC](https://forums.unrealengine.com/t/unwanted-rotations-of-collision-primitives-from-blender/2332873 "2025-02-14T18:36:41Z")\ **Posts on this page:** 16\ **Page:** 1
**Author:** ![BEZDUSH](https://d1ap1mz92jnks1.cloudfront.net/user_avatar/forums.unrealengine.com/bezdush/32/1028440_2.png) [@BEZDUSH](https://forums.unrealengine.com/u/BEZDUSH)\ **Post date:** [February 14, 2025, 6:36pm UTC](https://forums.unrealengine.com/t/unwanted-rotations-of-collision-primitives-from-blender/2332873/1 "2025-02-14T18:36:41Z")
Hello, everyone! I have a problem when exporting a custom collision, box primitives have unwanted rotation angles. When scaling the object, the collision is scaled on the wrong axes. Scaling and rotation applied. Naming is correct. What am i doing wrong? Blender 4.2.6 UE 5.5.1 > **img** > > ![image](https://d3kjluh73b9h9o.cloudfront.net/original/4X/2/9/f/29f7c331c040346e9147ce16f94a22b543c49290.jpeg) > ![image](https://d3kjluh73b9h9o.cloudfront.net/original/4X/e/2/c/e2cad1da4df27bcbca8636ff4118e501b5cfefa5.png) > ![image](https://d3kjluh73b9h9o.cloudfront.net/original/4X/9/f/d/9fd4dd2c7b2d1465edf1bb1da0681a8fc35ea8f0.png) [CollisionIssue.blend](https://forums.unrealengine.com/uploads/short-url/9IDgQnk3jY8URKPnz9RlQj6PZq4.blend) (1.1 MB) ---
**Author:** ![ClockworkOcean](https://d1ap1mz92jnks1.cloudfront.net/user_avatar/forums.unrealengine.com/clockworkocean/32/1169999_2.png) [@ClockworkOcean](https://forums.unrealengine.com/u/ClockworkOcean)\ **Post date:** [February 15, 2025, 7:57am UTC](https://forums.unrealengine.com/t/unwanted-rotations-of-collision-primitives-from-blender/2332873/2 "2025-02-15T07:57:58Z")
It’s a golden oldie, apply all transforms… 🙂 ![image](https://d3kjluh73b9h9o.cloudfront.net/original/4X/6/4/1/641d6f42da8c073fad203796476cedbba24dfdab.jpeg) ![image](https://d3kjluh73b9h9o.cloudfront.net/original/4X/7/c/3/7c3ad37c5a7f620c54e04fa27946ae43123f7ec7.png) ---
**Author:** ![BEZDUSH](https://d1ap1mz92jnks1.cloudfront.net/user_avatar/forums.unrealengine.com/bezdush/32/1028440_2.png) [@BEZDUSH](https://forums.unrealengine.com/u/BEZDUSH)\ **Post date:** [February 15, 2025, 10:16am UTC](https://forums.unrealengine.com/t/unwanted-rotations-of-collision-primitives-from-blender/2332873/3 "2025-02-15T10:16:31Z")
Okay. As advised, I applied all the transformations. But the problem is in the scaling of the object. The primitives have their axes swapped. This causes the collision model to not match the mesh when scaling non-uniformly. upd > **vid** > ---
**Author:** ![ClockworkOcean](https://d1ap1mz92jnks1.cloudfront.net/user_avatar/forums.unrealengine.com/clockworkocean/32/1169999_2.png) [@ClockworkOcean](https://forums.unrealengine.com/u/ClockworkOcean)\ **Post date:** [February 15, 2025, 12:19pm UTC](https://forums.unrealengine.com/t/unwanted-rotations-of-collision-primitives-from-blender/2332873/4 "2025-02-15T12:19:53Z")
I can find others talking about this, but I don’t see any solutions. In fact a block is enough here ![image](https://d3kjluh73b9h9o.cloudfront.net/original/4X/1/8/7/187c1b877988d479e9e8221bc34aaeb40c62a300.jpeg) Simplex collision is supposed to be simple 🙂 If you have a lot of simplex stuff, you might as well use complex, very similar ![image](https://d3kjluh73b9h9o.cloudfront.net/original/4X/d/a/c/dac71e81b9950f3473837606f7d3e5d2a8e21789.jpeg) I know that’s probably not what you were looking for 🙂 ---
**Author:** ![BEZDUSH](https://d1ap1mz92jnks1.cloudfront.net/user_avatar/forums.unrealengine.com/bezdush/32/1028440_2.png) [@BEZDUSH](https://forums.unrealengine.com/u/BEZDUSH)\ **Post date:** [February 15, 2025, 12:37pm UTC](https://forums.unrealengine.com/t/unwanted-rotations-of-collision-primitives-from-blender/2332873/5 "2025-02-15T12:37:05Z")
Complex collision be cheaper than boxes? o\_O (this case?) I use boxes as the cheapest primitives of suitable shape. Well, I’ll try to check it in 3ds max later. It’s strange that after exporting custom primitives, the boxes’ axes are rotated. I’m also trying to automate the production of modular assets. I use **send2ue** and **simple collider** for blender. Another example: > **Wall collision scale issue** > ---
**Author:** ![ClockworkOcean](https://d1ap1mz92jnks1.cloudfront.net/user_avatar/forums.unrealengine.com/clockworkocean/32/1169999_2.png) [@ClockworkOcean](https://forums.unrealengine.com/u/ClockworkOcean)\ **Post date:** [February 15, 2025, 1:39pm UTC](https://forums.unrealengine.com/t/unwanted-rotations-of-collision-primitives-from-blender/2332873/6 "2025-02-15T13:39:38Z")
> [@BEZDUSH](#): > > Complex collision be cheaper than boxes? o\_O (this case?) When you’ve hundreds of boxes, it’s about the same, I’d say. I think the problem is related to the orientation of each box, if it’s correct, it will stay put when scaled. Untested 🙂 ---
**Author:** ![BEZDUSH](https://d1ap1mz92jnks1.cloudfront.net/user_avatar/forums.unrealengine.com/bezdush/32/1028440_2.png) [@BEZDUSH](https://forums.unrealengine.com/u/BEZDUSH)\ **Post date:** [February 15, 2025, 2:13pm UTC](https://forums.unrealengine.com/t/unwanted-rotations-of-collision-primitives-from-blender/2332873/7 "2025-02-15T14:13:37Z")
Yes, collision boxes are oriented correctly. Rotation [0;0; 0]. ---
**Author:** ![ClockworkOcean](https://d1ap1mz92jnks1.cloudfront.net/user_avatar/forums.unrealengine.com/clockworkocean/32/1169999_2.png) [@ClockworkOcean](https://forums.unrealengine.com/u/ClockworkOcean)\ **Post date:** [February 15, 2025, 2:14pm UTC](https://forums.unrealengine.com/t/unwanted-rotations-of-collision-primitives-from-blender/2332873/8 "2025-02-15T14:14:36Z")
Maybe they need to have the same orientation as the mesh ( they are the collision for ), that’s what I read, somewhere… Just try one… 😉 ---
**Author:** ![BEZDUSH](https://d1ap1mz92jnks1.cloudfront.net/user_avatar/forums.unrealengine.com/bezdush/32/1028440_2.png) [@BEZDUSH](https://forums.unrealengine.com/u/BEZDUSH)\ **Post date:** [February 15, 2025, 2:22pm UTC](https://forums.unrealengine.com/t/unwanted-rotations-of-collision-primitives-from-blender/2332873/9 "2025-02-15T14:22:04Z")
Thanks for the quick replies in the thread! Do you mean the orientation of the mesh? Or the orientation of the collision box along the longest side (0\_o very strange idea). The rotation of the mesh and the primitives are the same, actual state. upd: By the way, rotation of primitives does not affect the final export. ---
**Author:** ![ClockworkOcean](https://d1ap1mz92jnks1.cloudfront.net/user_avatar/forums.unrealengine.com/clockworkocean/32/1169999_2.png) [@ClockworkOcean](https://forums.unrealengine.com/u/ClockworkOcean)\ **Post date:** [February 15, 2025, 2:26pm UTC](https://forums.unrealengine.com/t/unwanted-rotations-of-collision-primitives-from-blender/2332873/10 "2025-02-15T14:26:37Z")
Yes, I mean the transform of this collision primitive, for instance ![image](https://d3kjluh73b9h9o.cloudfront.net/original/4X/8/7/e/87e08295b268fe4bde92acbcdefd3f17d9ede7b4.jpeg) needs to be the same as the mesh part. It was just a guess… 🤔 ---
**Author:** ![BEZDUSH](https://d1ap1mz92jnks1.cloudfront.net/user_avatar/forums.unrealengine.com/bezdush/32/1028440_2.png) [@BEZDUSH](https://forums.unrealengine.com/u/BEZDUSH)\ **Post date:** [February 15, 2025, 2:42pm UTC](https://forums.unrealengine.com/t/unwanted-rotations-of-collision-primitives-from-blender/2332873/11 "2025-02-15T14:42:58Z")
Tried it. Any rotations are ignored. Is it just me who has this problem? ---
**Author:** ![Extrone](https://d1ap1mz92jnks1.cloudfront.net/user_avatar/forums.unrealengine.com/extrone/32/906554_2.png) [@Extrone](https://forums.unrealengine.com/u/Extrone)\ **Post date:** [February 15, 2025, 3:10pm UTC](https://forums.unrealengine.com/t/unwanted-rotations-of-collision-primitives-from-blender/2332873/12 "2025-02-15T15:10:37Z")
Using UCX\_MeshName\_## to create convex primitives instead of UBX\_MeshName\_## for box primitives is a workaround. might not be what you’re after but it scales correctly. ---
**Author:** ![BEZDUSH](https://d1ap1mz92jnks1.cloudfront.net/user_avatar/forums.unrealengine.com/bezdush/32/1028440_2.png) [@BEZDUSH](https://forums.unrealengine.com/u/BEZDUSH)\ **Post date:** [February 15, 2025, 3:15pm UTC](https://forums.unrealengine.com/t/unwanted-rotations-of-collision-primitives-from-blender/2332873/13 "2025-02-15T15:15:00Z")
Yes. I tested it, UCX I mean. But, am I alone with the problem of importing boxes. Maybe it’s a bug and requires a report? ---
**Author:** ![ClockworkOcean](https://d1ap1mz92jnks1.cloudfront.net/user_avatar/forums.unrealengine.com/clockworkocean/32/1169999_2.png) [@ClockworkOcean](https://forums.unrealengine.com/u/ClockworkOcean)\ **Post date:** [February 15, 2025, 3:16pm UTC](https://forums.unrealengine.com/t/unwanted-rotations-of-collision-primitives-from-blender/2332873/14 "2025-02-15T15:16:19Z")
> [@BEZDUSH](#): > > just me who has this problem? I think most people don’t construct collision this exactly, so it just doesn’t occur that often? ---
**Author:** ![BEZDUSH](https://d1ap1mz92jnks1.cloudfront.net/user_avatar/forums.unrealengine.com/bezdush/32/1028440_2.png) [@BEZDUSH](https://forums.unrealengine.com/u/BEZDUSH)\ **Post date:** [February 15, 2025, 3:23pm UTC](https://forums.unrealengine.com/t/unwanted-rotations-of-collision-primitives-from-blender/2332873/15 "2025-02-15T15:23:09Z")
Mean everyone uses convex and that’s it? Maybe it’s not critical anymore. ---
**Author:** ![system](https://d3kjluh73b9h9o.cloudfront.net/original/4X/7/1/3/713c9d3f58553f0de89543d76a8a3a2779dc9fa4.png) [@system](https://forums.unrealengine.com/u/system)\ **Post date:** [March 17, 2025, 3:24pm UTC](https://forums.unrealengine.com/t/unwanted-rotations-of-collision-primitives-from-blender/2332873/16 "2025-03-17T15:24:07Z")
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