Direct x 11 Tesellation and parallax map question
polycounter lvl 14
Hi I have seen the awesome videos of tessellation enabled environments with direct x 11 , tough my question is what does it need to achieve those reliefs? A normal parallax map or there is a new entry in the subject like a tessellation map or what?
Replies
But yes, you do need a dx11 graphic card.
isnt this vector displacement the same as normal map?
Out of interest to those who have experience with the subject, is the displacement storable in the magnitude of the vector? kind of like a bent normal map.
hmmm you would need to add two steps in order to do that, first get the length ( the length would be the magnitude of the displacement) of the vector (for now called n, n R^3) by calculating |n| and then calculate your normalized normal vector by dividing it with |n| again ( n0= n/|n| ) I guess it would be better for the performance to just store it in a texture :poly121:
e:// on the other hand you would save memory... I dont know does anybody of you know if this is applicable or if it is used anywhere?
position + displacement
why would you need to mess with the vector at all? just like r_fletch_r said you can use the magnitude of the normal just as is. It's mostly a matter of precision, but essentially your normal-map stores "direction + length".
When they are what you say they are, sure both of you are right sry for me messing things up here XD
and yeah you can get that displacement then
Yes, but if you didn't normalise them and instead stored a displacement value in the magnitude of the vector. You would have direction and magnitude. It doesnt need to be normalised if its not being used for lighting.
aside from that off the top of my head Modo, 3D Coat, X Normal
to render out Vector Displacement Maps.
Specter: max supports rendering those maps in mentalray with a plugin written by wayne robson. It was called Psycho Core, Wayne stopped distributing it becuase of the amount of support requests people were sending him (it was free).
Normal maps are not vector maps
Vector maps have an extra info on distance of displacement?
Tessellation will need vector maps?
yes.
Tesselation is just the division of faces. It can be used for a few things. displacement being one of them
What i wonder is how these things are calculated. can they even be generated between arbiary meshes? Its very hard to imagine how.
I mean for a mesh sculpted from a base it would I imagine be relatively simple to work out the transformation.. infact you probably allready have the information in memory on a per vertex basis... but how the hell would it work between arbitary meshes.
correct me if i am wrong, but the cry engine is not freeware open source yet like UDK is right? Which leads me to ask if the other favored engines like udk unreal engine and marmoset has this feature in it.
i believe this will take away the retopology workflow for good if we can just use our lores base cages as the final mesh. awesome..
these images show firstly, the material setup used, and secondly it's effect. it tesselates the mesh based on camera distance (if you just use a constant2vector node, the mesh will be permanently tesselated, which is bad for performance). the alpha channel in the normalmap just housed a regular grayscale displacement map.
now... if i'm looking at the material input nodes, could the world position offset node be used for the vector displacement map? or rather... could you use the RGB channels for the vector map, and the alpha channel for displacement, and simply plug RGB into world position offset, and alpha into displacement? or is that not how it works?
"the alpha channel in the normalmap just housed a regular grayscale displacement map."
i generated the displacement map in xnormal, i'm currently unaware of how to render out vector displacement maps, if i could, i'd be experimenting already. but at this point i'm focusing on getting my art good, and learning the tech later.
Here's a picture demonstrating the problem. The sides of the "wheel's" crack open. I know this thing wasn't designed for tessellation. But I took the high resolution bumper I use for baking and brought it into udk and it cracked at uv seams and smoothing groups. I don't have a picture since I am at school. But the one I posted above should demonstrate what I'm talking about.
Edit: Seriously though, I don't think there is any solution to your problem, other than doing something to your model and the UV's and smoothing groups.
Honestly I think its a bit counter intuitive to use displacement on an object like this, certainly just using enough geometry in an optimized fashion to get the proper curves would result in better performance than sub-dividing your model to 10,000,000 tris or whatever you need to do to get this effect.
In addition to that, displacement maps are not a replacement to normal maps. You will still need normal maps, especially in the distance where LODing on your displacement will mean the loss of important details. So when you think about it that way, you need to use a normal map *anyway* you're better off just making a nice looking lowpoly with normals.
Just use 2x the tricount you normally would, i'm sure you will get a very nice and very round result, that will still run better than slapping displacement on an object like this, and of course, cause less trouble.
Also Pn cracks along UV seams and smoothing group seams unless you can bake your heightmap using PN tessellation (not sure of a baker out there that does this).
It looks like this (old picture sorry). It gives me more than enough polygons to give it a nice smooth silhouette. I imported the car with it's smoothing groups and it cracks at them. The cracks aren't noticeably big, but can be seen if you are specifically looking at them?
-edit- This picture does now show the tessellated version. It doesn't even have uv's.
By the way, the tessellated car I posted up there was this model.
I figured I could just skip the normal map since it wouldn't provide any useful information since there was more than enough polygons to show the detail.
ps vector displacement probably isn't going to get popular in games ever (except for flat surfaces?), since you have to uv map your highpoly to match your low poly's uvs exactly.
I think you should do a bit more research on standard asset creation workflows, as this seems a bit half-baked.
could EQ or Jordan maybe help with this? also, what (in your opinions) are the most optimal settings in xnormal (or the app of your choice) for generating your hightmaps?