Battlefront's Level Construction - how can everything just sort of match and blend?

Panupat

This video was posted in Slack group.



What I was really impressed was at the 0:40 mark when the guy dropped a piece of ground on the ground and they just blend together so well. No visible seam. I'm wondering what's the trick here, how can that be possible.



Also towards the end of the video where he placed huge rocks onto the terrain and once again there's like no seam at all.

Can anyone share some insight please?

rollin

If you look closely at 0:45 you see that the ground texture is in world space and so you can easily blend the ground-element

Panupat

rollin said:

If you look closely at 0:45 you see that the ground texture is in world space and so you can easily blend the ground-element

oh.... ..... .... I'm not sure, that shadow pattern moving on top makes it really difficult to tell if the texture follows the asset or not. But that's a really neat idea.

tadpole3159

They have a couple of tricks here for sure

Notice the world space terrain material on the mesh? on the bottom? if you skim through the video a bit you can see the exact same material used as part of the terrain as well

next up we have detail maps, check this out when he scales the rock, the small stones and what not are mostly done via detail normal map it seems. That'll help blend it with the terrain for sure


Now we get to the best part, the seam stuff, check this out. Look at the intersections between the rock and terrain.

I don't think it's thats detail normal map because I think I can see colour coming though. I thought at first it's another terrain material fading in at the intersections but the colours that are fading in are exactly the same as the terrain underneath, it almost looks like the rock is going transparent at the intersections.

I have no idea whats going on at the intersections and would really like to find out. anyone from dice here?

rollin

cool, thx for making the gifs!

Mirbobo

Could the smooth blending be some sort of a depth blend or would that be too heavy on the performance?

Panupat

Vertex alpha driven by real time AO?

xvampire

well
from what i see, 
the normal doesnt seems technically welded and blend ,
however, the uneven surface from the geo , normal map and texture make it look like blended naturally ,:)

tadpole3159

xvampire said:

well
from what i see, 
the normal doesnt seems technically welded and blend ,
however, the uneven surface from the geo , normal map and texture make it look like blended naturally ,:)

but that fading texture effect at the interections is even affecting parts that arent quite intersecting yet. Look towards the middle of the rock in the gif above, it's getting close to the terrain and is starting to fade in some other textures.

leleuxart

There was a thread about the blending of the meshes with the terrain, but I don't think anything really came out of it other than it just being special Frostbite magic. You can achieve a similar affect in Unreal with the Pixel Depth Offset and the DitherTemporalAA node, although that's just a soft blend with whatever the asset is intersecting with. 

The rest of the stuff I think is just the use of world-space textures. In one of their talks(GDC I think), they mentioned how a majority of the photo-scanned meshes didn't really use the actual photo-scanned textures for the final look. The diffuse was softened for the colors only, while the actual detail came from the detail maps. The first mesh with the roots works just because it shares the same texture as the terrain, otherwise it doesn't look like it's doing anything special.

Panupat

Thanks Leleuxart. I'll need to check those 2 nodes out.

And what about the normals?  There seem to be no hard edge at all where the model meets the ground, how can they blend that?

tadpole3159

http://www.gdcvault.com/play/1023272/Photogrammetry-and-Star-Wars-Battlefront
this video explains everything Thanks leleuxart for the heads up

Jakro

To add, around 50-53 minutes in it explains how they do it.

In short the scale of a terrain object affects the tiling of the detail map so that tiling is consistent regardless of whether you scale up or down. Other than that I believe they just kept the values of their terrain objects and the global terrain very similar. There's a few ways to do this in unreal for sure.

Thanks for that GDC talk though, really amazing work 

Teessider

Thanks for the GDC link :chuffed:
It seems most of the techniques seen in the video can be recreated in other engines too.  

doc rob

They also adjust the vertex normals and tangents to match between the terrain and the terrain meshes.

Olmo

Hey guys, I'm working on a landscape-blending tool inspired by Battlefront as my Graduation Project, so I thought it might be relevant to post here . I used the Distance Field functionality in Unreal to achieve my results. If you are interested, I made a big post about it here : http://polycount.com/discussion/181140/unreal-4-terrain-blending-tool-inspired-by-star-wars-battlefront/p1?new=1