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[BUG] grass MESH on terrain with wind grass blows all over

Discussion in 'Developer Preview Archive' started by Chaoss, Oct 23, 2012.

  1. Chaoss

    Chaoss

    Joined:
    Jul 8, 2011
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    This is kind of a hard bug to explain, I have created a custom grass mesh (It's 1 plain rotated at a 45 degree angle for better birds eye view density), the pivot is placed near the base, and the object has been rotated 90 degree on it's axes (3dsMax export bug) and imported. It appears to apply fine to the terrain, however upon running the game the grass seems to blow all over the place and not on it's pivot. Unity is reading the pivot correctly.

    If I apply lots of grass and turn the banding up, it sort of looks like a grassy wave. It'd be awesome if you guys could fix this. Normal grass 'texture' works fine without issues however it does not fulfill my needs.

    also setting the random height to anything more than 1 makes some areas of the grass 'invert' and are up-side-down under the terrain. The grass is orientated corectly as it is randomly rotated on it's Y axes (the way it's supposed to be). There's something definitely not right here.
     
    Last edited: Oct 23, 2012
  2. makeshiftwings

    makeshiftwings

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    May 28, 2011
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    3,350
    Unfortunately, this bug has been around for years and they show no sign of fixing it.
     
    ROBYER1 likes this.
  3. Chaoss

    Chaoss

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    Hmm I've figured out a way around this bug... paint the base of the meshes vertex alpha to 100% (or was it 0%, it's one or the other) that seems to have fixed it
     
  4. antenna-tree

    antenna-tree

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    This isn't a bug, it's a feature to control the amount of wind that affects the mesh. You need to vertex color the detail meshes where 0% alpha equals no wind and 100% alpha equals full wind.
     
  5. Reanimate_L

    Reanimate_L

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    And why is this not documented?
     
  6. makeshiftwings

    makeshiftwings

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    Weird, I never knew that. It would be nice if instead there was an option to just have the wind value zero at the bottom of the mesh and one at the top of the mesh. That would be good enough to use the majority of details people put on terrains, which are mostly plants rooted to the ground, without having to mess with vertex painting.
     
  7. antenna-tree

    antenna-tree

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    Yeah, this could be automated or manually tweaked within Unity.

    As I've said publicly many times in the past, the Terrain Engine is over 5 years old and woefully out of date. As a Unity employee I'm probably not supposed to admit such things, but it's sort of ridiculous to try and make excuses for a part of Unity's toolset that is in desperate need of updating. All I can say is that it's on the table to be reworked in the 4.x cycle.

    The current Terrain Engine is still capable of great looking stuff though. One only has to look at the environments being made by botumys , Michael O, or larsbertram1 to see that people can creatively work within the current limitations. But while creating unique content is all about thinking outside of the box we still want to make it easier for everyone.
     
  8. wccrawford

    wccrawford

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    2,039
    I'd say that admitting such things is part of what makes Unity great. If your boss gets upset about it, you send them to me. ;)
     
  9. superpig

    superpig

    Drink more water! Unity Technologies

    Joined:
    Jan 16, 2011
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    4,649
    Yeah I'm with wccrawford. As far as I'm concerned you guys don't admit this sort of thing enough. It's not like not admitting it somehow makes it not be true; we'll discover it for ourselves as soon as we try using the features concerned, and we'll waste a lot of time in the process, which is just frustrating. You guys already know where the problems are; maybe talking about them will put off some amateurs who don't understand that all software has bugs, but it actually endears you to a person with a professional attitude because you're being up-front and they know more clearly what they're getting into, can plan around it, better judge risks, etc.

    Like, you guys already experienced what happens when you say you will deliver something and then you don't. It's pretty much the same if you say you have delivered something (like a terrain engine that can do all the things a modern game needs it to do) but in practice you haven't.

    (All this said I can imagine there are issues with talking about it on public forums too much, as people will find old threads and not realise that the issues may have since been fixed. This is why a public bug tracker would be better).

    (Also I don't think Michael O's using the terrain system, I think he has handcrafted terrain meshes).
     
    Last edited: Oct 31, 2012
  10. antenna-tree

    antenna-tree

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    The "not supposed to admit" thing was just an offhand remark and I think most of the Unity devs that interface with the community are honest with their opinions... and of course no one is telling us to do otherwise.

    The ones that I've pulled off the Asset Store to have a look at have used a combination of Terrain Engine and hand placed meshes.
     
  11. Chaoss

    Chaoss

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    Jul 8, 2011
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    antenna while you are here can I make 1, very easy request to implement into the next beta release, the ability to add color+normal maps to our terrains with detail maps for close up range, This is a very common and industry standard way of constructing terrains that Unity appears to be missing. I'm sure it wouldn't be that hard to implement.