Home Technical Talk

Virtual terrain textures rathern than meshes?

polycounter lvl 14
Offline / Send Message
NAIMA polycounter lvl 14
Hello , what does it means in this video ...

https://youtu.be/xKWa4WoTkV4?si=VN3DlsGFhklLXHaz&t=1766

Virtual terrain textures rather than meshes?
What is batch rendering?
What is machine learning super resolution technique?

Replies

  • gnoop
    Offline / Send Message
    gnoop sublime tool
    What time is it  in the video?
  • NAIMA
    Offline / Send Message
    NAIMA polycounter lvl 14
    gnoop said:
    What time is it  in the video?

    What you mean ? I linked to the actual starting point .
    Ok for some reasons seems it didn't work ... check from 29 minutes onward.
  • Eric Chadwick
    You have to format the link without the mobile URL (youtu.be) so it looks more like this, but unfortunately Vanilla Forum software doesn't support timestamped embeds, FML. So you have to copy/paste the URL into a new tab or window.
    https://www.youtube.com/watch?v=xKWa4WoTkV4&t=1766s


  • Eric Chadwick
  • poopipe
    Offline / Send Message
    poopipe grand marshal polycounter
    Virtual texturing generally refers to a mechanism that allows you to only stream in the the parts of a texture that you can see at the mip level that you can see. 

    Unreal has its own implementation but everyone else will be building it on top of directx12 

    It should be largely transparent to the artist and really just means you can throw a lot of texture data around in a more efficient way than with conventional dx11 type streaming 

  • NAIMA
    Offline / Send Message
    NAIMA polycounter lvl 14
    Yes , but what does it means, " instead then meshes" ? What are they referring to ?
  • poopipe
    Offline / Send Message
    poopipe grand marshal polycounter
    it looks like they send the terrain to the GPU as a texture and generate the mesh there instead of making a mesh and sending that to the GPU. This isn't exactly revolutionary  - in fact, it's generally what you should be doing. 

    you don't have to store lods, you can take advantage of your texture streaming system, you can have smooth lodding, you don't have to calculate when your lods arrive cos it's based on mipping  and GPUs are far better at handling textures than anything else.
    There are some disadvantages - like it being more difficult to do occlusion culling - but the advantages far outweigh the disadvantages. 
    I'm about 99% certain this is how unreal handles landscapes - it certainly stores them as textures in memory at runtime 

    i think where star citizen is being clever is the scale it's working at - its very, very large
  • gnoop
    Offline / Send Message
    gnoop sublime tool
    poopipe said:
    it looks like they send the terrain to the GPU as a texture and generate the mesh there instead of making a mesh and sending that to the GPU. This isn't exactly revolutionary  - in fact, it's generally what you should be doing. 

    you don't have to store lods, you can take advantage of your texture streaming system, you can have smooth lodding, you don't have to calculate when your lods arrive cos it's based on mipping  and GPUs are far better at handling textures than anything else.
    There are some disadvantages - like it being more difficult to do occlusion culling - but the advantages far outweigh the disadvantages. 
    I'm about 99% certain this is how unreal handles landscapes - it certainly stores them as textures in memory at runtime 

    i think where star citizen is being clever is the scale it's working at - its very, very large

    So it's like dx 11  tessellation and displacement . I always thought that  it's sort of more expensive than just  doing  the  mesh and lods. While indeed simpler to do.     Is it other way around now?    As of occlusion culling  it could done in patches , right ?  So  we would see un occluded patches  displaced. 
  • NAIMA
    Offline / Send Message
    NAIMA polycounter lvl 14
    I am actually not understanding the technique .
  • Eric Chadwick
    That’s ok, it’s not important to artists. That link I shared is more relevant, most likely.
  • poopipe
    Offline / Send Message
    poopipe grand marshal polycounter
    gnoop said:
    poopipe said:
    it looks like they send the terrain to the GPU as a texture and generate the mesh there instead of making a mesh and sending that to the GPU. This isn't exactly revolutionary  - in fact, it's generally what you should be doing. 

    you don't have to store lods, you can take advantage of your texture streaming system, you can have smooth lodding, you don't have to calculate when your lods arrive cos it's based on mipping  and GPUs are far better at handling textures than anything else.
    There are some disadvantages - like it being more difficult to do occlusion culling - but the advantages far outweigh the disadvantages. 
    I'm about 99% certain this is how unreal handles landscapes - it certainly stores them as textures in memory at runtime 

    i think where star citizen is being clever is the scale it's working at - its very, very large

    So it's like dx 11  tessellation and displacement . I always thought that  it's sort of more expensive than just  doing  the  mesh and lods. While indeed simpler to do.     Is it other way around now?    As of occlusion culling  it could done in patches , right ?  So  we would see un occluded patches  displaced. 

    Hardware tessellation is modifiying a mesh - there's no need for that in this scenario. It'll be a simple, regular heightfield grid with conventional smooth lodding just like you see in most game engines. the new/clever part is in how they stream texture data. 

    They mention patches and its the obvious way to manage that sort of thing so I expect you're correct in terms of occlusion culling.  

  • gnoop
    Offline / Send Message
    gnoop sublime tool
    poopipe said:
    Hardware tessellation is modifiying a mesh - there's no need for that in this scenario. It'll be a simple, regular heightfield grid with conventional smooth lodding just like you see in most game engines. the new/clever part is in how they stream texture data.

     I am still  not sure I understand the reason.  if it's regular grid mesh patches  and they displace it by height  textures in real time  it's still a hell lot more vertexes then  properly re-meshed  around terrain features model  with  lods.      More data to load , more math to do in  real time?   

  • poopipe
    Offline / Send Message
    poopipe grand marshal polycounter
    not really no

    When you're stood on a 1km square tile at 1m resolution you're handling/rendering a million verts with a static lod
    in the same scenario on a heightfield with smooth lodding you ditch  a shit load of those vertices 

    that's before you consider the other reasons
    1: you have to get those meshes to the GPU every time they lod
    2: you have to generate thousands (if not millions) to cover a planet
    3: you have to generate (and store) the lods
    4: you have to iterate on all this. 

    Storing it all as textures means you don't have to send shit to the GPU all the time (which is very slow) and that you get your lods for free
  • gnoop
    Offline / Send Message
    gnoop sublime tool
    Thanks  poopipe , it makes sense .        Stiil  the properly tessellated/decimated   mesh  around  terrain surface features may need much less vertexes than a regular grid.     Like several times less  but my guess it still  more traffic toward the GPU than  just textures .

Sign In or Register to comment.