Are power 4 displacements safe to use?

Discussion in 'Mapping Questions & Discussion' started by Unregistered HyperCam 2, Aug 18, 2018.

  1. Unregistered HyperCam 2

    Unregistered HyperCam 2 L3: Member

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    After reading this line in the valve developer commentary:
    "Be cautious when using power 4 displacements, as physics colliding with them have been known to cause fatal errors."
    I figured I should ask here whether it is safe to use power 4 displacements or are they game breaking in some sort of way? Also the situation does require the power 4 ones because I am working on a large map with a high level of detail needed.
     
  2. Idolon

    aa Idolon the worst admin

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    Don't use them. Power 4 tends to cause crashes. Instead, chop your brush up into four and make each a power 3 displacement. It works the same, but doesn't have the same problems.
     
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  3. Unregistered HyperCam 2

    Unregistered HyperCam 2 L3: Member

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    I've actually done that already but the map is way too big, so I wasn't sure but after seeing this comment and reading more about the topic I guess that's a no. thanks for responding.
     
  4. fubarFX

    aa fubarFX The "raw" in "nodraw"

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    high density power 4 displacements are an issue yeah. if you want to test it out, you'll usually crash when a ragdoll hits the displacement.
     
  5. Unregistered HyperCam 2

    Unregistered HyperCam 2 L3: Member

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    The density is quite low, I've got a big arse map but everyone says you shouldn't use them so I guess I won't
     
  6. Berke

    Berke L2: Junior Member

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    I allways use power 4 displacement in my maps but i don't ever see a issue happening.
     
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  7. Crowbar

    aa Crowbar Spiritual preprocessor

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    Power 4's are harmless with low enough density and lower powers are as dangerous with high enough. However, VBSP won't "compress terrain data" in a map that uses power 4 displacements, so yeah, just don't use them.
     
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  8. Unregistered HyperCam 2

    Unregistered HyperCam 2 L3: Member

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    Interesting, you're probably the first person I've heard that coming from
     
  9. henke37

    aa henke37

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    Unless you are seriously starved for faces, just use multiple lower power displacements so that you get that compression.
     
  10. Krazy

    Krazy L3: Member

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    badlands uses power 4 displacements without any problems
     
  11. ics

    aa ics http://ics-base.net

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    Power of 4 displacements cause a performance hit. Even if you manage to use them correctly, the map takes more memory to render and this in part can cause issues.
     
  12. Unregistered HyperCam 2

    Unregistered HyperCam 2 L3: Member

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    I had no idea how controversial this subject is haha thanks everybody!
     
  13. Harritron

    Harritron L4: Comfortable Member

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    I recommend that you don’t use them at all unless it is in an area where nothing at all can touch it.

    One of the maps on the imp a few weeks ago crashed everyone’s games because a Heavy’s ragdoll touched one of the power 4 displacements.
     
  14. tyler

    aa tyler

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    This makes it sound like you're using one massive brush for a very large area of space (or a small number of brushes at any rate). Is that right? That is absolutely not what you want to do, if so.