HELP: Basic shapes and grouping Created 8 years ago2015-05-13 16:59:05 UTC by Mr.Psilocybe

If I have a few spheres that are inside of each other and I group them, will they be rendered properly in game? Like, wha... how does the engine act with that? I can just leave shapes inside of each other right?

Example screen-capture:

Short answer: No. Especially with things like cylinders or spheres. Doing so will cause unpredictable errors.

Long answer:
Having brush-based objects inside of each other will cause the engine to clip the solids when the map is compiled, so that anything "inside" the shapes is gone and the faces will be cut. Having complex shapes inside of each other like in the above picture will cause these cuts to be somewhat unpredictable and very messy - and due to rounding errors, you're likely to have "holes" in the objects and collision errors that will get you stuck. You can stop this clipping by making some of the spheres a func_detail so they don't clip with "regular" world brushes, but func_details clip with each other as well, so you'll want to make sure they don't overlap.

Models can overlap like that without causing errors, so if you want a shape like that, you might want to look into converting it into a model instead.

Compilers will cut it for you and discard all faces that arent visible, cutting it manually so that things arent stuck in each other could help avoid some bugs and lower poly count but what you did is still a pretty good way to make random interesting shapes, nothing bad with it

Grouping in Hammer doesn't affect the in-game render. However, a lot of complex, overlapping shapes may cuase serious issues.
You should turn that into a func_detail entity by pressing ctrl+t.
However, I don't Think that overlapping brushes is such a good idea. It will probably split it up into an unnecessary amount of polygons (rendered triangles) and may cuase serious issues. Try to avoid overlapping brushes whenever possible.
A single look on that image tells me it won't work in-game.

EDIT: When I wrote and posted this, the two above posts hadn't been posted yet, so sorry for any repeated information.

If you're doing this for Source, Might I recommend using Models (prop_static) or Displacement terrain -Linky.
Rather than a func_detail, I would make a func_illusionary, and put a simplified collision brush overlapping it.

Sources displacements are ugly, people dont know how to use them, your noobish method is way nicer looking

Overlap brushes at will, unless you're getting visual errors in-game. Also while staying within your total

Objects

budget, and performance is good

Compile often to catch/repair any visual glitches that may pop up.

Note using VHLT compiler tools will minimize on errant shadows caused from overlapping solids. VHLT is not for Source. Ignore this suggestion. -mod

edit
Durr! Yeah no, if this is source you have no worries, just func_detail anything intersecting. Source does a good job smoothing things, especially in CSGO

func_detail seem to work just fine, actually.

Thank you all for the advice.