When is it (not) ok to let brushes clip each other?

Discussion in 'Mapping Questions & Discussion' started by kinggambit, Oct 25, 2013.

  1. kinggambit

    kinggambit L1: Registered

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    I was wondering if there was a rule of thumb to follow for letting brushes clip.

    I'd usually have to cut my brushes to all fit each other like a jigsaw, but I feel like it's just inefficient and leads to poor performance (i.e. a 10-sided room with just 1 floor brush vs multiple floor brushes fashioned to fit within the walls' dimensions).

    I heard brushes clipping can cause bad lighting and weird visleafs.
     
  2. Faux Rhinoceros

    aa Faux Rhinoceros Also known as Dr. Element

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    I usually just try to make sure there Are no visible overlapping faces. You should Aldo be careful not to have airpockets in solid, viscutting geometry
     
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  3. LeSwordfish

    aa LeSwordfish semi-trained quasi-professional

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    Brushes overlapping CAN cause that sort of thing, however it's the exception rather than the rule. Generally you're safe to overlap, and you can start making things more complex if they cause problems.

    The only time brushes overlapping is a bad idea is if you have two faces with different textures at the same place. This is called z-fighting and looks ugly since the textures flicker back and forth between two options.
     
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  4. Beetle

    Beetle L9: Fashionable Member

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    I thought it did that whether the same texture was being used on both faces or not.
     
  5. A Boojum Snark

    aa A Boojum Snark Toraipoddodezain Mazahabado

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    In general, there is nothing wrong with overlapping brushes. If everything looks ok, it is ok.

    "air pockets" don't matter in that case. VBSP uses entities to determine what is the inside of a map (hence leaks), and if there is any enclosed space without an entity it is considered void and culled from the map. Leaving pockets in non-world geometry is the problem, since it won't count as enclosed and you will have extra faces rendered.

    If they are both world brushes (or part of the same entity), having the same texture (including alignment) should cause the faces to be merged and/or one will cull the other, however you look at it. I also want to say that two differently textured world brushes won't z-fight because one will cull the other, but I am not positive.
     
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  6. Beetle

    Beetle L9: Fashionable Member

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    oh. well I've always just tried to perfectly align all word brushes and not care (unless it's simple) when it comes to entity brushes. I guess that's why I've only ever seen obvious overlapping of faces.
     
  7. grazr

    aa grazr Old Man Mutant Ninja Turtle

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    Aligning world brushes can cut down on unnecessery vvis cutting of visleafs and reduce waterindices. But mostly it depends on how anal retentive you are about that as most of the time the actual impact on performance is negligable.
     
  8. Faux Rhinoceros

    aa Faux Rhinoceros Also known as Dr. Element

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    I learned something from this thread. gg.
     
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  9. ForbiddenDonut

    aa ForbiddenDonut

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    Never.

    -Love, my OCD.
     
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  10. Beetle

    Beetle L9: Fashionable Member

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    I remember when I did mapping with TFC and it was crazy important. oh the good ol' days