LOD workflow?

montana2008

Hi all, Could somebody please point me to a tutorial about designing game assets with LOD in mind.

I have to model (LOD 0) vehicle at 150,000 tris
and (LOD 5) at 2000 tris.

What is the best way of tackling this? does the game engine handle this or do i have to make each LOD mesh etc?

i know the general idea of LODS and why they are used, i would appreciate a tutorial which covers it in more detail though. please help if you can?

Steppenwolf

My workflow is usualy to try and keep workable loops intact in the low poly. Then as i go deeper into the lod's remove loops and small elements, further down i remove some bigger elements aswell and only keep the big shapes that define the silhoutte. When you have cylinder shapes work with side numbers that can be easily halfed like 16 to 8 to 4 so you can just remove every other loop/ring without messing up the silhouette.

Then in the last lod i also target weld a bunch of vertexes, not bothering about messing up the uv layout. Can't be seen on that distance anyway.

EarthQuake

Wow you have to go from 150K down to 2K? That seems really, really excessive. Steppenwolf's advice is good though, basically what I do as well.

In addition, try to use as few uv islands as possible. When you get down to the lower counts how low you can push it depends entirely on how many uv seams you have, and thus need to keep to not mess up the uvs.

montana2008

thanks very much for the advice guys. Thing is i've done the hi poly first. DO you guys know of any tutorials or workflows going from hi poly to low LODS?

yeah earthquake, 150k to 2k..its big jump isnt it.

Steppenwolf

Remove support loops, retopo and optimize a bunch a stuff where you see fit, then follow steps from my first answer.
Or are we talking about a car for a racing game that was done without subdivisions?
If you could show some wires that would be helpful.

montana2008

thanks for ur help steppenwolf, if i remove loops and retopo wouldnt the UVs and silhouette change too much?. ill try and send you some wires asap.

Steppenwolf

Well you retopo before you unwrap. Could it be ther's a confusion about the terminology? What is the 150k model to you, a hipoly or a low poly?

To me a hipoly is a subdivided mesh with hundredthousands or millions polygons that is used to bake out maps. But if you indeed made a car for a racing game with lots of geo instead of normal maps then things are a little different.

montana2008

hey steppenwolf. ive sent you a PM hope u dont mind