‫So this is just going to be a quick lecture on trying to understand why we're getting this weird glitch
‫here when we move from the right of this first spawn point.
‫Now, let's dive straight into this one without an introduction.
‫The idea here is that something must be going wrong with the collisions, collisions being those simplified
‫meshes around the world that allow us to do physical, physical calculations.
‫Basically, what can we stand on?
‫What can we not?
‫Because they're often simplifications of the meshes that we can actually see for performance reasons.
‫So how do we see what the collision world looks like?
‫Well, fortunately, in our viewport we can go to the lit mode, the button that by default says lit
‫at the top left.
‫And you can see as different view modes here.
‫Some of them are things like unlit removes the lighting.
‫You can see the wireframes of the meshes, but the one we're interested in is either the player collision
‫or the visibility collision.
‫Now the difference being that the visibility collision is the more fine grained meshes and the player
‫collision is that coarser grain mesh and you can kind of see the difference there.
‫I think that's quite obvious.
‫When you click between the two, you can see the coarse grain and fine grain nature of things.
‫But if we move over here from this particular angle, you can see that there is a mesh just poking through
‫here, a collision mesh that we do not want.
‫Where is that coming from?
‫Looks like an error in our asset pack.
‫If we click on it, you can see it says floor filler 27.
‫Not very helpful.
‫That's the name of the actor.
‫But if we go and have a look at its static mesh component and the details pane and have a look at its
‫actual static mesh, we've got the SM stairs, a one.
‫Now if we browse to this asset using the little magnifying glass and open it up, then we're going to
‫get the static mesh editor opened up in Unreal.
‫And what we're interested in is having a look at collisions.
‫So to see collisions, you go to this collisions button and you can click on both the simple and complex
‫collision that shows you there's two different measures here.
‫The complex collision is for when we're doing finer grain physics and is often the same as the visible
‫mesh.
‫And then there's the simple collision, which is just a kind of course of grain version, as we've been
‫saying.
‫And you can kind of see that difference there as a nice coarse grain mesh.
‫And what happens if we have a look, if we've got this coarse grain, simple collision selected and
‫go below the floor is you can see there's this massive strand going off down there into the distance.
‫That must be what was causing us our collision issues.
‫A little bit of an error in the asset pack.
‫Few ways that we could deal with this one might be if you go to the collision menu, you can remove
‫collision, which is entirely removing collisions.
‫You can then regenerate it using a bunch of different options that are built into unreal, such as you
‫can add a sphere for simplified collision, a capsule box ten DOP 26 DPI.
‫Lots of different options here.
‫Auto convex collision.
‫We're not going to do any of that because actually we can fix this up pretty straightforwardly.
‫Oh yeah.
‫One more option would be that we could set the complex collision as the simple collision.
‫There's an option for that in the details pane, but we're not going to go down any of those routes
‫because actually you can do a little bit, of course, grain mesh editing right here.
‫At least we can delete some vertices.
‫So if we go ahead and select it while the collision mesh simple collision meshes visible, you can select
‫this set of edges or the face that goes all the way down here.
‫And you can see that's all that's selected.
‫That's the only thing that's changed to a lighter green color.
‫That's how you can tell.
‫And if we add delete, then you can see that goes away and it doesn't actually affect the rest of the
‫mesh.
‫The rest of the mesh is pretty solid, still looks pretty much as we would want it to look.
‫And if we go even in this viewport, we can go over to the player collision view and you can see what
‫that mesh looks like.
‫It's a little bit funny in places, but it will work.
‫So if we go back to Lit.
‫And then go over into the sandbox.
‫You can see now that little shard has disappeared from our player.
‫Collisions can go back into lit and hit play.
‫And now if I go over to the right and move around here, there are no collision errors whatsoever.
‫And because we modified that stair mesh, let's go down the hallway and try going up and down the stairs.
‫Yep.
‫The collisions there still seem to be functional.
‫I'm not dropping through the floor or anything.
‫I'm able to go up them and it's not a kind of discontinuous jerky motion.
‫So Astaire mesh is now fixed and you've learned as a result of it a little bit about how collisions
‫are set up against static meshes in Unreal.
‫The next lecture we're going to be going back to animations and understanding the animation blueprint
‫to create much more complicated animation behaviors.
‫I will see you there.