3D game glitch when traversing my world

Hello! I appreciate your help! I am a teacher using Construct 3 in a game design class. Unfortunately, our student desktops are around 8 years old, so I have not been able to have much experience in creating 3D games. I have a student working on their own laptop on a Minecraft clone game, and they have created an amazing world!

They only problem that we have found so far is that when the player is traversing the world forward there's no problem, and the game autopopulates the world just fine. However, when you turn around to try to go back to retrace your steps, the world creates these giant gaps (pic below) in the ground that the player can fall through. So far, it appears to just be when you are exploring where you have already been. Going forward is fine.

I am stuck on trying to fix these holes. Any help would be appreciated. Thank you!

https://drive.google.com/file/d/1z-0f6B9-P1n9_0BjAexARajeuyi3faZz/view?usp=sharing

3d is ambitious, especially for 8 year olds.

Anyways, here are a few ideas to help debug it.

Since it seems to have to do with loading chunks as you move around, you could just make the camera have a top view to help see what’s going on.

If it’s leaving gaps moving one way then maybe it’s overlapping the other way.

When creating the chunks are you creating them relative to the player or to fixed chunk locations? A collision will occur after some overlap which can get worse with lag. Maybe that’s something to consider.

If nothing obvious stands out I’d consider redoing the chunk system from scratch. You can prototype it fast in a fresh project in 2d if you like. That would be much easier to debug and identify shortcomings. You could even do it in 1d, like a side view platformer to get the chunk idea working with minimal effort. I personally find that designing something on paper first makes it way more robust than doing it all in code as you go along.

Thank you for your quick reply! I apologize, but the desktops are 8yrs old. The students are 13-18. I do have student who swears up and down that they had never used a mouse until this class, so all ability levels too.

I believe that the chunks are populated as the player moves along and relative to the player's position. That's a fine idea about overlap. I will give that a shot. The top view is an interesting idea too, I will see if the student likes that.

Anyone else is welcome to weigh in! I don't want to be that guy in a forum who says "NVM, I figured it out. Topic closed 4 years ago"

Thank you so much for your help! It appears to be an issue with the chunks overlapping as they are created - then trying to be created again on top of the old as the player backtracks. If I remember, I will post the final version of the game once it is complete. Again, I appreciate your assistance!