# Collision Thickness **URL:** \ **Category:** Cesium for Unreal\ **Created:** [May 17, 2021, 12:27am UTC](https://community.cesium.com/t/collision-thickness/13659 "2021-05-17T00:27:31Z")\ **Posts on this page:** 8\ **Page:** 1
**Author:** ![mahalobay](https://sea2.discourse-cdn.com/cesium/user_avatar/community.cesium.com/mahalobay/32/4112_2.png) [@mahalobay](https://community.cesium.com/u/mahalobay)\ **Post date:** [May 17, 2021, 12:27am UTC](https://community.cesium.com/t/collision-thickness/13659/1 "2021-05-17T00:27:31Z")
Hi devs, Would it be possible to expose collision thickness? In the more extreme edge cases, I can crash through the ground terrain in my setups. On unreal landscape meshes, I managed to clamp this by setting collision thickness to 10000 (100m). I tried searching for the parameter in the 3D Tileset component but it doesn’t have that option - possibly because it’s a collision mesh instead of a landscape mesh? Alternatively, any suggestions to preventing crashthroughs appreciated. Thanks! Alan ---
**Author:** ![nbaja](https://sea2.discourse-cdn.com/cesium/user_avatar/community.cesium.com/nbaja/32/3458_2.png) [@nbaja](https://community.cesium.com/u/nbaja)\ **Post date:** [May 17, 2021, 8:05am UTC](https://community.cesium.com/t/collision-thickness/13659/2 "2021-05-17T08:05:09Z")
I do this: [Stick to the ground - #2 by nbaja](https://community.cesium.com/t/stick-to-the-ground/13576/2) ---
**Author:** ![mahalobay](https://sea2.discourse-cdn.com/cesium/user_avatar/community.cesium.com/mahalobay/32/4112_2.png) [@mahalobay](https://community.cesium.com/u/mahalobay)\ **Post date:** [May 19, 2021, 10:59pm UTC](https://community.cesium.com/t/collision-thickness/13659/3 "2021-05-19T22:59:35Z")
Unfortunately I’m not trying to stick anything to the ground 😑 In extreme cases I have things colliding with the ground plane at 400kmh… I am computing altitude with a line trace though so it’s possible I could add in a check for “was 20m above the ground going 400kmh = crashed” ---
**Author:** ![nbaja](https://sea2.discourse-cdn.com/cesium/user_avatar/community.cesium.com/nbaja/32/3458_2.png) [@nbaja](https://community.cesium.com/u/nbaja)\ **Post date:** [May 20, 2021, 7:45am UTC](https://community.cesium.com/t/collision-thickness/13659/4 "2021-05-20T07:45:03Z")
Yeah exactly. So if you keep track of how far they traveled the last frame, that will give you a good enough idea of how far they’re going to travel next frame. Then you can shoot a ray out of the forward vector of the airplane that length, and you’ll have a good idea as to if they’ll crash next frame. If they will, trigger your crash event and stop all of your movement calculations. On the next frame, move the airplane to that spot where the trace collided, add some offset so that it looks correct. Then the airplane will look like it actually hit the ground, if you want them to be able to see the crash. Yank the camera out of the cockpit, do a slow 360 degree arc around the airplane at a good altitude, bring up a menu or something letting them know “you crashed, what now?” ---
**Author:** ![nbaja](https://sea2.discourse-cdn.com/cesium/user_avatar/community.cesium.com/nbaja/32/3458_2.png) [@nbaja](https://community.cesium.com/u/nbaja)\ **Post date:** [May 21, 2021, 9:01am UTC](https://community.cesium.com/t/collision-thickness/13659/5 "2021-05-21T09:01:34Z")
Oh, there’s also the dynamic pawn: ["Added a dynamic camera that adapts to height above terrain" - #2 by Nithin\_Pranesh](https://community.cesium.com/t/added-a-dynamic-camera-that-adapts-to-height-above-terrain/13600/2) I haven’t gotten to try it yet, but it is probably going to be less hacky than what I described above. ---
**Author:** ![mahalobay](https://sea2.discourse-cdn.com/cesium/user_avatar/community.cesium.com/mahalobay/32/4112_2.png) [@mahalobay](https://community.cesium.com/u/mahalobay)\ **Post date:** [May 21, 2021, 7:43pm UTC](https://community.cesium.com/t/collision-thickness/13659/6 "2021-05-21T19:43:37Z")
I’ve already built a pawn that does that exact same thing… Thing is, I WANT to fly at super-speeds near the ground, it’s quite exhilarating 🙂 ---
**Author:** ![nbaja](https://sea2.discourse-cdn.com/cesium/user_avatar/community.cesium.com/nbaja/32/3458_2.png) [@nbaja](https://community.cesium.com/u/nbaja)\ **Post date:** [May 24, 2021, 7:41am UTC](https://community.cesium.com/t/collision-thickness/13659/7 "2021-05-24T07:41:04Z")
hahahaha please share video if it’s allowed 🙂 ---
**Author:** ![mahalobay](https://sea2.discourse-cdn.com/cesium/user_avatar/community.cesium.com/mahalobay/32/4112_2.png) [@mahalobay](https://community.cesium.com/u/mahalobay)\ **Post date:** [May 24, 2021, 7:02pm UTC](https://community.cesium.com/t/collision-thickness/13659/8 "2021-05-24T19:02:35Z")
Early test from last month. This isn’t the superspeed flying version though unfortunately - just me driving my space rover down the freeway 🙂 [![](https://global.discourse-cdn.com/cesium/original/2X/1/19b5dcac7ea4099c1341f7a225614e445c6d7d14.jpeg "Orbital Preview NetMode Standalone 64 bit Windows 2021 04 07 08 48 16") ](https://www.youtube.com/watch?v=ctg3Ns2NPNI)