Unity 4 tessellation and how it works?

That's great that unity 4 will now support tessellation. Does anyone have any good resources or information as to how to go about modeling to support that? It subdivides the mesh, but does it use some sort of mapping to get details?

Thanks!

 

you can check out NVIDIAs tech documentation, demos and code on the matter, they have a plentora. I think ati has a few too

 

Aras - Maybe you can give me an overview as to how it's done in Unity. Does it tessellate using a normal or displacement map?

 

You should include some examples or have some integrated shaders, especially for us "artist" types.

 

What do you mean? Detail tessellation with displacement map is 100 times better than tessallation by default without any maps used. Detail tessellation can make great visual results on rocky surfaces or buildings and is defenetly whorth it, while subdivision without maps can be usefull or not, but in most cases it is not worth performance impact. No need to implement detail tessellation for characters like Crytek did, in my opinion total waste of performance. Characters are already constructed of many polygons and normal map pretty much cover a lot, there is almost to none difference with tessellation. You can even check how Metreo 2033 used tessellation which is complete waste of performance, but hey using detail tessellation on really flat surfaces (1-100 polys) with lots of relief is huge visual gain.

 

I am wondering how does tessallation (in Unity) handle sharp edges. Are those completly being smoothed out? For example if there is cube, is it subdividing it the same as for example 3ds max Turbosmooth or Zbrush subdivision or are faces being smoothed out really close to their edges? And is subdivision procedure handled by developer or player on objects that have it (how many times is it done)?

 

have examples of at least 2 different techniques for it please. your users will love you more.


Personally speaking I like the idea of tessellation for "strange" fx which includes hair but also for other tricks

 

Oh ok then we are going to wait for miracle and hopefully someone will make those shaders avalible on Asset store.

 

Hi,
Would it be possible to have some links to example hull and domain shaders ?
MSDN does not seem so helpful.
I also try to find a way to create and test hull and domain shaders ( in a non - unity context for now ), any links would be much appreciated.
Thanks in advance,
-Ippokratis.

 

Unity:

are UDK and cryengine providing out of the box tesselation shaders to use? if so then you don't want to be the ginger haired stepchild of game development do you?

 

Yes they do

 

Please Aras, I don't care if you do built-in tessellation shaders or not, it's not really your job. But for StarTrek's sake write us some DOCUMENTATION on Hull Domain shaders (any new syntax, built-in functions, managing the pipeline etc) for us to do the rest.
I loved you so much for Surface shaders Aras so don't disappoint us BTW can we write a hybrid of a vertex/geometry/pixel/tessellation shader in one nice surface shader? would be catastrophically awesome.

 

No... Please Aras, write us some sample shaders so that we can see how to map this NVIDIA and Microsoft documentation to Unity. That is far more important, and don't waste time on repeating the information...

For me the most interesting cases are Terrain tessellation based on height/displacement maps. And detail tessellation for meshes.

 

Example Tessellation shaders:

1. fastest 3d package style mesh smooth without smoothing groups and threshold (artists used to doubling edges for creases)
2. the above but edges handled by smoothing groups
3. detail (parallax shader) alternatives with detail derived from normal map or conversion of normal map into height map (or just a heightmap).

That would do out of the box although I suspect you can skip step 2. Artists are all used to subdivision surfaces / mesh smoothing a low poly cage in modelling packages so if they can do the same workflow in unity, that would just be fantastic, yes. Let the artists dictate the way forward here. After all, they will be the ones trying to make it look right.

Look at how modelling packages smooth and subdivide, it's a good start. But getting that going fast is the challenge, no doubt

 

I have to say, Terrain tesselation would be absolutely brilliant! As would normal detail map tesselation, but man my mind is exploding with possibilities in regards to terrain...

 

Thanks Aras... well, a detail "parallax mapping replacement" and normal map replacement would be my best bet for it rather than any dramatic change to topology.

 

Exactly.

While tesselation may not be *needed* for dynamic objects, like characters and monsters, for obvious reasons, the feature would be a HUGE time saver and quality increaser for environments.
NO WAY at the moment to make decent stone walls, just to give a first easy example.
Another vantage: no need to model the stones that much: just give the main hull and then... texture.

I understand there is the hard choice "Unity team or user team" but I think that saving a lot of work by doing it integrated would be much better.
At least, you could integrate some shaders for static objects, that would do the trick for 90% of the use of tesselation.

 

Is there a benefit over LOD with tesselation, if you have the ability to just open up your modeling software and add geometry/subtract geometry the same way? I don't see why you wouldn't just do that, unless tessellation is better on performance. There are a plethora of ways to upscale/downscale geometry in modeling software whether you want it smoothed or not.

 

I figure that by now you have seen some amazing tessellation demos? It seems like it can provide millions of free detail polygons, and increase detail massively and do all kinds of special effects, so all in all tessellation is amazing, even averts the necessity for "LOD mesh" etc.
for a nice example of a special effects based on tessellation, run on the aliens and triangles demonstration: www.youtube.com/watch?v=1c_PVtMIz-A‎
and the endless city thing with the skyscrapers in it.

 

Here are some nice tessellation shaders that I use:https://www.assetstore.unity3d.com/en/#!/content/17442