Download

Level Design 101: splitting geometry, removing faces, and subtractive brush issues

I’m still learning the basics of UDK and am looking for some more 101 style tutorials to cover such basics as mentioned in this topics title. I watched some youtube tutorials and googled a bit but I suspect my vocab is not helping in the hunt so here goes a few noob questions:

Is there an easy way to split basic geometry? By split I mean if I create a floor and I decide I want to cut it in half later, how would I do that?

Is splitting geometry a recommended method?

Is there a way to merge simple geometry?

How can I remove a face from a cube but not end up with the weird “invisible perspective”. I know that sounds really stupid. I’m basically wanting to create something like a box without a lid. It will actually be the opening of a fireplace. If I just remove one side the perspective gets really weird.

Finally, I’m having some issues with the subtractive brush. It seems like it doesn’t work on some of my walls. Or, if it does work it will only have a partial affect on one side. What causes this?

You should not be ‘making’ much of anything in UE4 or UDK. BSP brushes are not anywhere near as efficient as models made in a real modeling package like Blender or Max. You still have to convert it if you even want to get close. Look at the examples and turn off ‘Static Meshes’ (those made outside of Unreal) and you’ll see 90% of the level disappear. Nobody models in Unreal. You’re asking to learn to do something that you might as well learn in another program anyway. That having been said there is a geometry ‘mode’ in the upper left hand corner that does what you’re asking.

Well that’s bad news :frowning: Not really wanting to be a heavy 3d person anyway just looking to get a feel for things. For giggles I may try and finish off this first little project of mine as editing the BSP’s doesn’t seem too bad. As someone else told me I can always convert the BSP objects to mesh’s so I’m not too concerned with that at the moment. What I’m wanting to do would seemingly be simple tasks in a basic 3d editor, so I’d still like to know how to do them in unreal still. Split, merge, and delete geometry faces without occlusion culling effects.

Hi Myoelectric,

I’d suggest going to this link: https://www.youtube.com/playlist?list=PLZlv_N0_O1gaCL2XjKluO7N2Pmmw9pvhE -This is all UE4 Video Tutorials then start with the “Intro to Level Design” series. The intro is long and gives an overview, but videos 1, 2, and 3 jump right into what you’re trying to achieve. Also, BSP’s are fine as long as you’re just playing in the editor. When you package a game, however, these assets will cause a significant reduction in frame rate. However, as you’ve mentioned, you can always convert your BSP’s to static meshes if you like that workflow.

I know this thread is a few months old, but for the benefit of the OP if they’re still interested, or anyone else who hits this from a search as I did…

Your description of the “weird perspective” issue sounds to me as if you’re seeing the expected result of deleting a face from a one-sided mesh (and this is not an Unreal-specific behavior). In game engines as well as 3D content creation tools like Blender, Maya, or 3D Studio, most of the polygons in the mesh will be one-sided, because rendering the hidden inside faces would waste GPU resources. If you remove a face from a cube, you’ll see the other faces from either the inside (where they will, by design, be invisible) or from the outside (as before, since the other faces haven’t been changed by you deleting one). Whether you are looking at each face of the cube from inside or outside depends on the orientation of the cube and camera in your viewport.

In level editing (and again, this is not Unreal-specific), this one-sided rendering is extremely helpful if you want to create a level where the player camera is close to their in-game character’s position so they see a ceiling or roof over their head. But you as the designer don’t want to have to be zoomed in that close for editing. If the ceiling or roof meshes are one-sided, they will render to the game camera from the inside but will be invisible to your viewport camera while editing. You’ll edit the level with an almost omniscient top-down visibility, but your players will have an immersive fully-enclosed experience.

This also applies when editing something like a cottage or house if the interior is a separate mesh from the exterior. The walls will typically be rendered only from the inside, so you can place furniture, lights, and props with ease but your players will still see a fully immersive level from the inside. Likewise the exterior mesh will render only from the outside, to save resources at runtime.

I am new to Unreal myself but experienced in other environments, and I’ll add my +1 to the excellent replies from others. My focus is more programming than design, but I’ve learned enough Blender to be proficient (though not expert) and create medium-complexity models. The BSP Brushes in Unreal are a useful prototyping tool, but coming from Blender or Maya or 3DS these feel very confining. Even as a programmer, knowing some 3D modeling has empowered me in several ways:

  • If I need a prototype to test my programs, I don’t need to rely on someone else having time to create it.
  • If I have a commercially-produced model with a minor problem, such as some flipped or missing triangles, I can fix it myself quickly.
  • Knowing a little about another team member’s job helps me appreciate their work more, and helps me communicate better with them on collaborative projects.

3D modeling tools can be daunting if you approach them in an effort to learn the entire tool, but perhaps try thinking of it another way: Learn to use one of the tools (Blender is free for anyone, and the Autodesk tools have academic editions that are free or inexpensive), but set your initial goal modestly: “I will learn ______ tool just enough to do what I could have done in BSP.”

That level of learning will give you everything you could have done in BSP, but now you have taken the first steps down a longer 3D modeling road that won’t dead-end at that first waypoint. If you never need to go further, you still have the needed capability for your projects, but if you do need to go further, you’ve got plenty of room to gradually increase your skill without switching tools.

Learning Blender or the other 3D modeling tools deep enough to create cinematic renders is a major undertaking. Learning these tools deep enough to create a window frame or a traffic cone is, however, quite an approachable task.

Hope this helps!