qhull precision error?

Discussion in 'Mapping Questions & Discussion' started by ethosaur, Aug 27, 2015.

  1. ethosaur

    ethosaur L3: Member

    Messages:
    107
    Positive Ratings:
    19
    So I got this error in my hammer logs today:
    "qhull precision error: Only 4 facets remain. Can not merge another
    pair. The convexity constraints may be too strong. Reduce the
    magnitude of 'Cn' or increase the magnitude of 'An'. For example,
    try 'C-0.001' instead of 'C-0.1' or 'A-0.999' instead of 'A-0.9'."

    The map works fine, but im worried it could somehow cause some bad errors.
    There is a lot of displacements on my map, and im pretty sure it's what caused this.

    I tried searching on google for this error but only found one forum that was on here long ago that never really covered how to fix it.

    Should I be worried? How should I narrow the bug down to find it? Thanks

    Full compile log: "
     
    Last edited: Aug 27, 2015
  2. Vel0city

    aa Vel0city personal pick-pocketing parrot

    Messages:
    1,884
    Positive Ratings:
    1,488
  3. ethosaur

    ethosaur L3: Member

    Messages:
    107
    Positive Ratings:
    19
    It did not come up with anything regarding my error, only some minor ones like colliding displacements here and there, missing studio model and a problem with the skybox. Otherwise nothing unusual.

    The web seems very dry of this error.

    Updated descrition with full compile log.
     
    Last edited: Aug 27, 2015
  4. Tumbolisu

    aa Tumbolisu  I ⌄ I 

    Messages:
    931
    Positive Ratings:
    895
    Error loading studio model ""!
    You have a prop_something with no model. It's a good idea to change that.

    I could imagine that the qhull error comes from super thin geometry. Or maybe displacements with weird settings. Do you have anything strange like that?
     
    • Thanks Thanks x 2
  5. ethosaur

    ethosaur L3: Member

    Messages:
    107
    Positive Ratings:
    19
    Thats what I was not sure of, but I did some weird thing that fixed it. But I really wish I knew what I did that fixed it. Basically just cordon off the area until the error shows up then delete that area, and copy it and paste in a older version where it works. (Atleast what I did)

    Bah..


    Also, where can I find that prop with no model?
     
    Last edited: Aug 27, 2015
  6. worMatty

    aa worMatty Repacking Evangelist

    Messages:
    1,071
    Positive Ratings:
    832
    You could use the entity report tool to search for all your props, specifying the studiomodel keyvalue and leaving the value field blank.
     
    • Thanks Thanks x 1
  7. ethosaur

    ethosaur L3: Member

    Messages:
    107
    Positive Ratings:
    19
    Didn't quite work, but I found another way to do it, I just ticked off all things on the map except props and found that little silly unused prop_static under the map.

    Now my console is almost completely error free, quite a sight to behold.
     
  8. Kill_the_Bug

    Kill_the_Bug L14: Epic Member

    Messages:
    1,455
    Positive Ratings:
    235
    Sorry for the bump but I too am now getting this error message and can't seem to find a solution. I didn't want to start a new thread since the title of it works and it's better to have the answers pertaining to the same item in one place (IMO) instead of multiple threads about the same topic.

    My map is also crashing on load into TF2 - worked great before, interlopers and alt+P show no errors

    Anyone know og a fix for the qhull precision error message?
     
  9. AsG_Alligator

    aa AsG_Alligator trigger_hiss

    Messages:
    358
    Positive Ratings:
    810
    Yeah... This error is the bane of my existence lately.

    Interlopers has nothing on it, but from my experience it may cause random displacement cracks on seams between brush faces.
     
  10. Pocket

    aa Pocket func_croc

    Messages:
    4,489
    Positive Ratings:
    2,213
    Should be easy enough to find by going through the VMF in a text editor and doing Searches for "prop_".
     
  11. Kill_the_Bug

    Kill_the_Bug L14: Epic Member

    Messages:
    1,455
    Positive Ratings:
    235
    Could not find in text editor - what exactly am I looking for?
     
  12. Kill_the_Bug

    Kill_the_Bug L14: Epic Member

    Messages:
    1,455
    Positive Ratings:
    235
    Ok, found the cause by using cordon block - somehow one of my brushes became as thick as a single grid line on the map causing the error, unfortunately my map still crashes on load into TF2
     
  13. Freyja

    aa Freyja ¯\_(ツ)_/¯

    Messages:
    2,819
    Positive Ratings:
    4,661
    I'm bumping this only because this is the thread that came up on google when I had the same error and I want to share my knowledge -

    This issue for me was caused by two things so far: A displacement that was too big, cutting it into multiple helped,

    And also, displacements in the skybox (that had been scaled down from full size displacements) being off grid. Snapping their verticies to the grid fixed it the second time it appeared.
     
    • Thanks Thanks x 3
  14. MOCOLONI

    MOCOLONI L5: Dapper Member

    Messages:
    223
    Positive Ratings:
    53
    Is there a way to locate the specific displacement that's causing the problem? It currently pops up on the compile logs but couldn't find the brush(es).
     
  15. Kill_the_Bug

    Kill_the_Bug L14: Epic Member

    Messages:
    1,455
    Positive Ratings:
    235
    Cordon box, or the big box method - if cordon, do a fast compile and locate the areas where it's NOT happening then start to shrink the box so you can find out where it is - you may have to do this 50 times. They are VERY hard to find.

    Oh and maybe this will help - did it just happen? If yes, can you remember what you were just working on? If yes, check those item as they may be the cause of the error.
     
    • Like Like x 1
  16. Freyja

    aa Freyja ¯\_(ツ)_/¯

    Messages:
    2,819
    Positive Ratings:
    4,661
    I had a test visgroup that I systematically added displacements to and hid it on compile of a basic VBSP only compile until I identified the offender.