Jump to content

Tessellation in Action

Josh

210 views

With tessellation now fully implemented, I was very curious to see how it would perform when applied to arbitrary models. With tessellation, vertices act like control points for a Bezier mesh that is subdivided dynamically in screen space. Could tessellation be used to add new details to any low-poly model?

Here is a low-res character model with a pointy head and obvious sharp edges all around his silhouette:

low.png.40d68ea31c5c8e3be595f385ae0a88e0.png

lo2.png.68867ca81ac75930436b9d6bdfa60af6.png

When tessellation is enabled, the sharp edges go away and the mesh magically appears more detailed:

hi.png.2a4d87e93b132291f21e9024be65c8a7.png

hi2.png.a8c3d8301da893632c14c20bf56efce8.png

Let's take a look at the "Doom Seeker" enemy model from Doom 3. The original model is 640 triangles:

lowres.thumb.png.2cebd36a72a3f63138cdaf2015c23984.png

wire.thumb.png.fd9c86255b3ff3acc0f06db87d252774.png

Tessellation gets rid of the blocky outline.

tess.thumb.png.d8b5037415bde4232a7519ab755b6cbb.png

And displacement adds new details to the model.

displacement.thumb.png.812ad3059f8e0c689d335d8837f641b3.png

displacement2.thumb.png.8acc599f36539ef21375af3907376ac4.png

What about other shapes? Can this technique be used to turn any low-poly model into a high-res version? Here is a tire model from "The Zone" DLC. Even with displacement set to zero on edge vertices, cracks still appear.

Image2.png.79c9bc4e7105f140a02a732376bc5b5e.png

So my conclusion on this is that tessellation is fantastic for closed organic shapes. In fact, I think it totally replaces separate LOD meshes for rocks, characters, and other organic shapes. However, it is not something you should use everywhere without any discretion.

  • Like 4
  • Sad 1


3 Comments


Recommended Comments

Very cool how you have implemented this. I remember a thread we had a few years ago talking about these possibilities. Glad you were able to work through the obstacles. 

Share this comment


Link to comment

But what's the advantage over LODs or even impostors? Is tessellation cheaper or more expensive?

Share this comment


Link to comment
3 hours ago, Genebris said:

But what's the advantage over LODs or even impostors? Is tessellation cheaper or more expensive?

  • Smooth transitions between detail levels.
  • Make one low-poly model and you're done.
  • Better detail up-close.
  • No need to adjust distance settings or anything, it just works.

 

  • Thanks 1

Share this comment


Link to comment

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Add a comment...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

×
×
  • Create New...