What is optimal 3D geometry for mobs and blocks?

[Kevin Tee]

I want to model a few 3d mesh for minetest usimg blender. What I want to know is...

Does mintest support non-manifold 3d mesh? Should non-manifold mesh be avoid?
3d mesh with intersect planes?
triangle or quad face?
Polycount?
Blocky model or it does not matter?
1 blender unit = ? Minetest unit
UV map texture is better to be power of two right?
What should be avoid for optimal performance?

Thanks

[Calinou]

1 blender unit = ? Minetest unit

As far as I remember, 1 Blender unit is worth 1 Minetest node (the length of a block).

Blocky model or it does not matter?

Obviously, if you want your model to look consistent with the world, it is probably going to be blocky. There is no however no restriction on this.

UV map texture is better to be power of two right?

Today's hardware has no problems with NPOT (Non-Power Of Two) textures, but this is not the case of older hardware (< 2006).

[ExeterDad]

Supposedly Minetest supports all meshes and textures that irrlicht supports. Personally I've only tried .x, .b3d, and .obj http://irrlicht.sourceforge.net/features/

Since Blender defaults to quads, that is what I've been using and Minetest doesn't complain. Triangle make my head hurt with Blender.

Polycount? Like any game... low is better. There's a lot being drawn in Minetest. A bit of a shame as all those voxels are drawn. If you aren't going for smooth curves you will be fine.

Blender unit? I've forgotton. I'm convinced it makes a difference depending on what format you are exporting. Others here have debated with me. Make your basic block .5 rather then Blenders default 1 and it will be less confusing.

Make sure normals are set correctly before export. Minetest is picky about them.

Make notes. Minetest/Blender documentation is scarce and spread all over the place. Maybe your notes will help yourself AND us in the future. I have at least 3 files I've made with Minetest/Blender notes, and I'm kicking myself that I don't know where I've put them.

[Nathan.S]

I'll agree with Calinou a blender unit equals one node in Minetest. I've been using obj as my format of choice as it is easy to open with a wide variety of programs and 1BU has always equalled a node in game, its possible that other formats might be different as ExeterDad mentioned. If you still have the default scene in Blender the default cube is 2BU so you need to scale it down to half of its size.

Intersecting faces aren't a problem, as long as they don't run in the exact same plane. If you have to faces occupying the same virtual space you will get a flickering effect as the engine won't know which face to draw, you'll actually get that effect in Blender as well.

[Kevin Tee]

Thank you everybody for information. I will model a few very soon.