Making Train station chair?!

mobpapst

hey guys,

i want to make this train station chair but i dont know how to do the highpoly right and iam struggleing how to end up with a good lowpoly result because all these wholes need a lot of geometry. so how to do it best. hope you can help me.

cheers

Eric Chadwick

Depends what kind of mesh design it is. Can you get a higher-resolution photo?

Also depends on your modeling software. What software do you want to use?

Skumtron

For the low-poly metal grill, you could try baking normal and transparency map from the high poly object:

[ame]https://www.youtube.com/watch?v=jGNSJeJ7sYQ[/ame]

mobpapst

Iam useing 3ds max.

here is a better photo what iam aiming for:

a3D

Max bakes. Or you can use xNormals, which is free.

Just don't expect the whole process to be easy. You've got a lot to learn when you start baking stuff. Luckily, Polycount wiki has everything you need

mobpapst

is it enough to bake these grid pattern on a "plane" and combine the normal map with an alpha one to get a good effect?

takeing for all this geometry with a 4/5 sided cylinder would cause to much polycount or how would you do this?

Eric Chadwick

I would create a highpoly model for one chair, including the support rails and the seat mesh, then bake the whole thing to a low poly model of the chair. The mesh is easy, I'd use a bunch of splines set to render (see Help for splines).

We have a baking how-to guide here
http://wiki.polycount.com/wiki/Texture_Baking

Eric Chadwick

And yes, bake an Alpha map. I'd use alpha test for the shader in-game (better performance than alphablend)

Eric Chadwick

Also, you could mirror the low-poly model, to improve texture resolution. Since its a symmetrical subject.

a3D

I would tile the grid and ignore the welds entirely, unless this was product viz or there are serious reasons not to tweak the model

Eric Chadwick

If you tile the grid, that means more draw calls, because you would have multiple maps. If you use a texture atlas, that makes it more complicated

a3D

I was thinking of overlapping UVs actually

Eric Chadwick

You mean, packing the tiled mesh texture and the tube-arms texture together into a single atlas texture?

Do-able, and gives better texture resolution, at the cost of more vertices and more UV work. If so, that's what I meant by more complicated. Sounds to me like this might be difficult for the OP.

The other drawback with a tiled texture is you don't have unique UVs for the seat and/or back, so you can't easily add butt-wear, dirt, etc.

Elrinion

You actually can tile a piece of an atlas texture in UE4. It's just that it requires a different material instance.

It can be done by subtracting the rows/columns where the specific tile is from the UV numbers in the texture sampler. The bad part is that you get MIP bleeding if you don't account for padding in the atlas.

Eric Chadwick

Here's a tutorial for that method (I think)
http://oliverm-h.blogspot.com/2013/04/how-to-create-ue3udk-texture-atlases.html

More here
http://wiki.polycount.com/wiki/Texture_atlas

Elrinion

That was it. There's some pretty clever stuff you can do with custom materials.

You could even use another UV channel to multiply the dirt and extra details over the tiling parts.

The problem is that these things start to get a little inflexible in a multiple asset pipeline pretty fast.

mobpapst

I've used splines for the stuff and bake it on y plane in xnormal an grabbed the alpha from the normal map. its works pretty fine. in my mat i used two sided aswell. the results are very good. thanks for the help guys