Walls are not solid

I created a maze using wall sections. There are a lot of wall sections. For some reason I can walk “In to” some walls from one side, but not from the other. If I go to the other side the wall is solid. This is random. Most walls block me from both sides but here and there I hit ones that let me in. All the walls have the same properties.

I’d start checking the basic setup first to get closer to the problem.

So check if the walls have their collision properly set up, with the collision preset set to “BlockAll” to block everything for now. Later, when it works, you can change it back to whatever suits you the best, though I guess BlockAll works just fine for solid walls anyway.



So you’re using the cube mesh from the engine to make the walls? Weird, there shouldn’t be anything wrong with them. If you delete the defective wall segment and place a new one, does the problem persist?

OK, that’s really weird. I took a “Good” wall section, did the copy/paste thing, and I can walk “In To” it.
Now to make life interesting… I can walk in to the wall from the “Y” axis on the… lets say left side for reference, but not the Right side. So I rotated it 180. No difference. I can go into the wall from the Left side, but not the right side. Not sure why the left side lets me in, but the right side does not. I can not enter either “End” of the wall. Then I separated the wall section from everything so it is floating in space. No change there either. I need to go look at all the other walls and see if all the bad sections are on the “Y” axis. I know I have one other wall with the same orientation that acts like this one.

I changed from “Default” to “BlockAll” and nothing changed. I created one block and then did a bunch of copy/paste instead of creating a wall section asset. That is another mistake I need to correct.
I have it set up so when I shoot something, sparks emit from the hit location. When I shoot a solid wall all is well. When I shoot a wall I can go “in to” I still get the sparks, but I end up with a lot of things that look like floating bubbles that really kill the system.
I have an earlier version of maze tucked away, so I opened it an selected the same wall section (cube46) and all is well there. It acts right. So someplace between that version and this one something went south. I guess I could start all over again from the old version. There are things I would like to change anyway.

Curious problem. I’m a bit at a loss here. I’m currently placing the cube mesh all over in hopes to recreate the issue, but to no avail for now. Had the thought that maybe negative transform values could cause funny collision behavior, but seems solid.
Also, “in to” means you can’t fully pass through? That’s why I suspected the collision of the wall might be inaccurate, but that doesn’t seem to be it. The capsule component of your character is intact as well I’m guessing?
In order to eliminate the character as the source of the problem, you could enable physics on a sphere or something and see how it collides with the wall if you push it towards the wall, to see if it can also pass through.

If you visualize the player collision, does it align with where the walls are?

Ok, I lied. When I expand the cube from default size to 10 x .5 x 5, then I can enter it, but again, only from the left. Let me play with the size to see what happens. Maybe something with the height of the wall vs the player height?

Everything is the same pretty blue color.

Just so I’m not making a mistake here, the dimensions are the same as in your project now?
Because when the collision is fine, and it seems to work on my end, the problem is probably not the walls. So my next question would be, can you enter any other geometry from the Y axis?

I’ll get the character going and see if that reproduces the issue. Is a strong suspect now.

I can enter a Cylinder and a sphere, but not a cone. Again, ONLY from the Y access.

I went to several more walls. All walls with a face on the left can be entered but only from the left face, including the ends.Here is the wall section setup:
The orientation indicator is in the bottom left corner of the screen and says X is straight ahead and Y is to the left.
The wall sections are 10 x .5 x 5 with MI_StoneWall03 Material from the Twinmotion Materials download.
Like I said, the original wall sections from the older save are fine.

I added a cube, and it works fine. I can’t enter it from any direction. The wall sections must have picked up an error at some point, or the project did.

If the walls are 5 high, I can enter them from the “Left” face. Once I drop the wall Height to 2, I can no longer enter them. 3 lets me in. I can’t tell where the height of my collision mesh from my character meets up to the wall. Maybe if the wall face is higher than my collision mesh this one single side will let me in. I am using the Twinblast character if that matters.

The Third Person Character works fine, so it has to be something in the twinblast character.

Same, except I have a capsule collision added to him. I also have an AIPerceptionStimuliSource.

The left Y face only is really driving me nuts along with the wall height.

Then here is the weird thing, the character behaves normally for me.
10 x 0.5 x 5 cube and twinblast character (and Unreal version 4.24.3) with no changes made, other than the scaling and orientation of the cubes. Here is a screenshot of the capsule collision, probably the same on your end.

Thinking out loud. We know

  1. the ThirdPersonCharacter works for
    reasons undetermined
  2. scaling beyond +2 on the Z axis, breaks collision
  3. only when moving from negative Y towards positive Y the collision breaks (so moving into the “left” most face of the object)

It’s really difficult to see a correlation here. Unless the capsule component is offset from the character, it shouldn’t be possible to move into an object with intact collision. And even then, scaling the wall wouldn’t or shouldn’t cause any change.

What I would do now, is making a copy of the character and remove and replace components like the capsule collision to see if that makes a difference and if so, closely compare what has changed.