Modelling a path on top of ground (for games). Also UV tiling question.
A question! With stuff like this:
How are the paths and dirt patches usually textured/modelled?
Would the entire surface be grass, then the dirt patches and path is geometry (path is curved geometry) overlaid slightly on top of it, with them being transparent so you can see the grass through? Like this:
Or would the path and dirt textures be applied to actual polygons on the mesh (so the path would probably be curved in the physical texture), and the texturing has the actual grass on the side of the textures? The main problem I can see that I'm curious about is the part where it curves vertically at the edge of the terrain. Would the overlay be only the flat path and the edge would just be a separate part of the UV map, or?
Not sure how this is usually gone about, and I'm interested! I can't tell if the path tiles or not.
Also what about the tiling grass? If I went with the first option, would the mesh for the grass be something like this? (More cleaned up though. And maybe just a grid because of the small deformations around the edges? In which case maybe you wouldn't need to have to do the UV tiling. Hm.)
Which is then flattened out and uv mapped so it's stretched out 5x+ past the bounds enough that the grass texture tiles to get the size right?
This would be for a game so you don't want to have to swap out textures much, but for something with a tiling texture like that is it better to literally have a single polygon for each tile of the texture (and pack the grass into the model texture itself), or do what I did there and swap to a separate "grass" texture for that. Judging by the background behind the scene, there has to be a tileable grass texture that takes up the full 0-1 UV space, so. I don't have much experience in tiling textures when UVW unwrapping a mesh rather than the standard way of 3D programs just plopping down materials wherever and setting the projection, however, so it's always been kinda foreign to me.
Which texture sheets would you say the sides of the terrain, (including the part where the dirt path ends), the path itself, and the dirt patches, be on? The top of the grass would be on a separate sheet if it tiles, but I don't know about where the rest would best go. One for each might be a bit of overhead, but maybe it won't matter with the small size of the maps?
Sorry if anything's confusing! I'll try and explain some things in better detail if you need!
Also excuse the bad diagrams!
How are the paths and dirt patches usually textured/modelled?
Would the entire surface be grass, then the dirt patches and path is geometry (path is curved geometry) overlaid slightly on top of it, with them being transparent so you can see the grass through? Like this:
Or would the path and dirt textures be applied to actual polygons on the mesh (so the path would probably be curved in the physical texture), and the texturing has the actual grass on the side of the textures? The main problem I can see that I'm curious about is the part where it curves vertically at the edge of the terrain. Would the overlay be only the flat path and the edge would just be a separate part of the UV map, or?
Not sure how this is usually gone about, and I'm interested! I can't tell if the path tiles or not.
Also what about the tiling grass? If I went with the first option, would the mesh for the grass be something like this? (More cleaned up though. And maybe just a grid because of the small deformations around the edges? In which case maybe you wouldn't need to have to do the UV tiling. Hm.)
Which is then flattened out and uv mapped so it's stretched out 5x+ past the bounds enough that the grass texture tiles to get the size right?
This would be for a game so you don't want to have to swap out textures much, but for something with a tiling texture like that is it better to literally have a single polygon for each tile of the texture (and pack the grass into the model texture itself), or do what I did there and swap to a separate "grass" texture for that. Judging by the background behind the scene, there has to be a tileable grass texture that takes up the full 0-1 UV space, so. I don't have much experience in tiling textures when UVW unwrapping a mesh rather than the standard way of 3D programs just plopping down materials wherever and setting the projection, however, so it's always been kinda foreign to me.
Which texture sheets would you say the sides of the terrain, (including the part where the dirt path ends), the path itself, and the dirt patches, be on? The top of the grass would be on a separate sheet if it tiles, but I don't know about where the rest would best go. One for each might be a bit of overhead, but maybe it won't matter with the small size of the maps?
Sorry if anything's confusing! I'll try and explain some things in better detail if you need!
Also excuse the bad diagrams!
Replies
The problem in why I'm not completely understanding how they do it, though, is where it wraps around; this chunk in particular:
What I'm thinking is it might be this (excuse the mess).
With red being a grass texture
Light blue being a dirt texture
Yellow being a side-grass texture
And Black being the geometry for the path texture which is floating above the rest.
But I'm curious how you'd do the corners, and the dirt side with some path bricks, if this was a dirt path overlay on grass.
So it can't be that exact workflow. That's where I'm stuck, basically.
Edit: I'm an idiot. Went and got a picture without the overlays.
Edit2: Managed to snap a pic of the other side of the path, if that's any help:
https://www.dropbox.com/sh/ylx95wkxkd32bbk/K1v8EVI1Vu
Hm. So you've have the grass on top, with floating path geometry (red).
You'd have grass->dirt texture on the side (yellow).
And you'd have Path_End texture on the light blue?
The only problem I can see with that is the path would have to end on a specific polygon (the path end on the left is different to the one on the right), so would they have specific Path_End textures for each possible polygon or I guess just make them per-use-case? Still seems a bit weird to me overall but hm. You could be right.
Edit: To the post above, I think you might be on the mindset that the path is a physically curved texture, to which I say I don't think it is! I think it's a straight texture that's curved via floating geometry. But the stuff about the side might still be correct.
Edit:
"Edit: To the post above, I think you might be on the mindset that the path is a physically curved texture, to which I say I don't think it is! I think it's a straight texture that's curved via floating geometry. But the stuff about the side might still be correct."
Well. Im just telling you some options. Who could tell how its exactly made, without seeing the wires?
1 texture is vram consuming but requires less gpu/cpu calculations than several objects/materials with alpha, and well, there's only that on screen anyway.
Not that it couldnt be done the ways you describe for more generic purpose (large terrain) but probably not as clean.
And i was wrong, the seams are obvious.
I still think the path is a huge splat with grass border painted on it, not curved shape. Looking at some screens, there are zone, that couldn't be done that way.
http://www.micromania.fr/zooms/PlayStation_3/disgaead2/disgaeaddeux019.jpg
If it were a huge splat wouldn't that use way too many resources in both storing a huge texture and loading it into runtime alongside all the other stuff it has to load? Also there's still a seam here..