Hello I was wondering if anyone knows how is done assassin creedi III Deep snow , where you see the player advance slowly according to the snow deepness , leave a track and deform the surface on the passage ... Is not a simple decal texture as the shape seems to be interactively deformed by the passage of the player and npcs...
Replies
here it is in unreal:
[ame="http://www.youtube.com/watch?v=0V6bit8PrZo&feature=share&list=UL0V6bit8PrZo"]Advanced Vertex Blending Material - UDK - YouTube[/ame]
starts using world position offset at 2:30
http://m.youtube.com/#/watch?v=EMMGye1myQY&desktop_uri=%2Fwatch%3Fv%3DEMMGye1myQY&gl=IT
this could be expanded to allow foot print masks per foot for bipeds that change depending on speed and action etc.
and if its lodded based on player or camera, you can control the performance impact?
is this actually in game? sometimes they res everything up, even if its in game, for cinematic captures or trailers etc.
edit, hard to say without seing it properly free cam, could also be a really well done form of parallax,
i kinda doubt its a dx11 thing considering
You can notice that the separate rock formations that are NOT terrain don't do the effect, only on the ground (terrain), that might be tesselation, but I can't say for sure without playing the game. Sega Rally Revo had a similar effect. I would still consider it being just decals with bump offset.
Seriously, it's very possible they just are using a simple Vertex-Offset (only visually, it doesn't affect the geometry of the terrain) which is subtract a certain value once the character collision is detected.
Since it will rely on the geometry of the terrain, it can be pretty cheap.
I haven't played AC3 but by the sound of it it seems very similiar to what was used in Sega Rally Revo.
4m25s in :
[ame="http://www.youtube.com/watch?v=Rdqeu-2bTT8;t=4m20s"]Sega Rally Revo Tech Demo - Surface Deformation and Graphics - YouTube[/ame]
If is a deform shader I dunno , perhaps it is but is performed on contact , perhaps is a kind of mesh item that is added over the normal terrain to simulate the snow and then is deformed when collided , but still there are different levels of pression and it also seems to be consistant and seamless with the flat terrain around ...
It is vertex displacement (world position offset in unreal), painted on the terrain. As the character moves though the painted area, he take away a set ammount of the painted colour, removing the "snow" or displaced vertexs in the shader, giving the appearance of the snow being push away, trodden down.
can't really explain it any clearer without you looking into the shader tech and playing with it yourself.
people are saying decals and maps are added on top of this, to create the "crumples" look of the snow, but IMO it would also just be done through a normal switch in the shader.
This is really only way to do this effect, other than actual mesh real time mesh deformation, which you don't want to do in a game like AC3...
SnowPrint v2.6.1
http://www.scriptspot.com/3ds-max/scripts/bake-vertex-position-from-modifier-stack
3dsmax Footprint Tutorial PT2 - YouTube
I noticed that it only seems to happen on ground terrain and not on things that might be static meshes, like rocks or logs. The part where he runs up on a large rock to get up into the trees, they seem to take care not to show the footsteps.
Since they have a custom engine that they have built more or less from scratch they probably have the the know how and power to pull this off. It's kind of a smart move actually, covering the world in a white snow texture, and I'm glad they solved the problem of making it behave like snow.
Just to be pedantic - it wasn't
They had dynamic subdivision on patch surfaces which is not the same thing at all.
You end up with some wonky results at times.
It is clear that is not a offset mapping but a true 3d displacement , that is more evident if is more high snow ... also since the snow seems almoust seamless with the terrain , is it possible that it coud be a kind of feature mapped directly over the terrain ?
perhaps some vertex coloring code ?that displaces the terrain at higher levels forming dunes and cliffs of snow of different heights? perhaps with a maximum height that never goes too far above the player's mid body ...
I think is very nice and I woudl like to know how they did implement this ....
"World Position Offset allows artists to modify vertex world position in the material editor, which allows arbitrary deformation effects and custom ambient animation for different types of objects.
this is why it is only on the terrain mesh and it looks odd on steep slopes
[ame="http://www.youtube.com/watch?v=cfTzUwDeUbM"]Unreal Development Kit - UDK - World Position Offset - YouTube[/ame]
whether they use a shader or a separate mesh (which would cause seams anyway) the methods and results are the same.
no other way to eplain it really, other than to download Unreal and copy the shader i linked to
can't really explain it any other way.
http://udn.epicgames.com/Three/DevelopmentKitGemsRealTimeDeformation.html
For those interested, the Xbox 360 does sport some early DX10 functionality including gpu tessellation that was used in Halo Wars with their vector field terrain. Here's a link to Colt McAnlis's GDC session (one of the my favs of that year) you can skip to "LOD Round3 - Hardware" section of the talk to get to it:
http://www.gdcvault.com/play/1277/HALO-WARS-The-Terrain-of
Tough I guess is different from the snow patch ?
In larger, more open games like AC3, the shader approach is more feasible
That's a video of Connor running in the snow - in case anyone was still wondering what it looked like.
It's a pretty cool effect, I enjoyed it.
http://www.slideshare.net/agebreak/uncharted3-effect-technique
Sorry to resurrect an old thread but i was wandering if this effect would be to costly for an online pvp type of game?
Regards Peter
http://www.dualshockers.com/2014/03/30/batman-arkham-origins-deformable-snow-tech-could-be-used-for-mud-and-sand-and-be-persistent/