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OPEN  Bug report #3408  -  Render problems with overlapping transparent models
Posted Oct 27, 2012 - updated Jan 28, 2013
alextishin (alextishin) has been working on this issue since January 28, 2013 (20:48)
Issue details
  • Type of issue
    Bug report
  • Status
     
    Open
  • Assigned to
     alextishin
  • Type of bug
    Not triaged
  • Likelihood
    Not triaged
  • Effect
    Not triaged
  • Posted by
     H-Hour
  • Owned by
    Not owned by anyone
  • Estimated time
    Not estimated
  • Category
    General
  • Resolution
    Not determined
  • Priority
    3. Normal
  • Reproducability
    Not determined
  • Severity
    Not determined
  • Targetted for
    icon_milestones.png Not determined
  • Complexity
    icon_customdatatype.png Not determined
  • Platform
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  • Architecture
    icon_customdatatype.png Not determined
Issue description
Item 3408 imported from sourceforge.net tracker on 2013-01-28 20:10:24

When two transparent models (foliage, bushes, etc.) overlap, the game seems to have a problem rendering one behind the other. This is noticeable in places where one transparent model partly obscures another one. From certain angles one of the models will disappear, or sometimes one model will completely obscure a second one.

In the attached image I've shown an example map that uses a low-lying model that covers all of the ground. This model has transparency to look like lush, low growth in a forest (ie - the soldiers walk through brush up to their knees). There are two bushes on either side of the soldier in the top shot, but only one appears. When I rotate the camera, the other bush appears, but as you can see the edge of one of the low-growth models slices through the larger bush. The sharp edge you see is where one low-growth model stops and another starts (they are built to tile seamlessly).

I have attached the screenshot, as well as a zip file which includes several files you'll need to put in the right place:

/ufos/map_low_growth.ufo (select the map in skirmish mode) /models/objects/vegi/low_growth/ (contains the md2 and skin) /maps/test_low_growth.map (compile to BSP)

I understand these kinds of bugs are difficult to fix. But this is the fourth map I have started only to stop because of rendering/compiling problems. If there is some way to find a solution to this issue it would be really great. I think I could make a really nice looking forest map that is pretty simple using this trick with low growth and clumps of bushes.
Comments Ported from Sourceforge  ⇑ top
natewr (2012-10-27 17:50:29.005000)  ⇑ top
low_growth.zip
alextishin (2013-01-18 14:05:43.369000)  ⇑ top
Known problem. Cannot be fixed completely because of limitations of current 3D hardware, but some workarounds are known. Will think on what is possible to do in our case.
Steps to reproduce this issue
Nothing entered.