Questions about Game mesh and retopo workflow

rayle1112

Hi folks!

I'm a game design student and this is my first thread on Polycount forums!

I'm working on the first game character for my graduate demo reel. I've finished the modeling stage and going to jump into the game mesh stage. (I'M STUCK AT THIS STAGE )

The character will be rendered in Marmoset Toolbag.







So my questions are:

1. Polycounts: The whole character (except the chimpanzee with dynamesh) has 500k Tris right now. I don't know exactly how low the game mesh should be. (<100k Tris, I guess?).

2. Posing: The chimpanzee hands and feet have to hold the controllers. Should I pose the character before or after the retopo stage? I think the character won't be symmetrical and much harder to retopo If I pose him right now.

3. Game mesh: (Stuck here) The whole model is combined with many different pieces. Some pieces are already in low poly. Can I just delete some edges? or they have to be retopoed completely.

For example: The hand is combined with many different parts like the image below. Should I retopo every single part or just combine everything and retopo the whole group? And also pieces with holes, do I need to close the holes and let the normal map does its job?



I would appreciate if anyone can show me some references of hard surface game mesh.

Thanks!

SuperFranky

Rule of thumb: Retopo everything as a continuous mesh if it doesn't have to be animated specifically.

You can and should use your existing topology as a base for low poly.

Quack!

100k tris is fine for a main character in a game nowadays, but you should only use that as a loose goal and use as many tri's as you need to define a good looking mesh, which is very subjective.

Main characters on console/pc will range from 30k to 200k this generation, depending on the game.

As for topology, you are going to have a pretty tough time, organic hard surface shapes are a pain in the ass to learn how to bake. Here are some rules of thumb to help you out.

1. Non-Destructively Triangulate your low poly model before you bake.
2. If you have a low poly edge that is >80° I recommend you chamfer that edge OR set a smoothing group/edge split there.
3. After you are finished UV mapping, before you bake, set your smoothing groups/split edges by your UV shells, there are scripts that do this automatically. Google is your friend.
4. Do a test bake very early on after you unwrap the parts, just use Auto-Uv Packing initially, when you are happy with the bake, then hand uv pack.

ZacD

Also you should model your high poly in ways that will make the lowpoly easier and better. Like those armpit wires, you might want to make it so a simple cylinder can capture more of that detail and have a few extra tubes that run along on top of the main cylinder.

rayle1112

Thank you guys!

I have another question. Do I need to care about the different materials? For example: This part has two pieces with different materials so should I keep them separated for easier texturing or retopo them as a continuous mesh?

throttlekitty

Unless the materials need wildly different and special shaders, it's generally best to do the lowpoly as one object. You can bake the materials out as simple flat colors for masking later when you do textures.

rayle1112

Thanks throttlekitty!

Also, can someone answer my question about posing? Is it possible to pose the low poly organic character (chimpanzee) after retopo? The hands of the chimpanzee are relaxed at the moment, but they should be to grip the controllers.

Quack!

Yea you can push and pull your low poly around as much as you want. That's how they work in games :]

Model the low in a pose that works best for you, which is subjective. In your case, model it in whichever pose it is easiest to make. When working in a team, your anim team will tell you how they like it.

rayle1112

Quack! wrote: »

100k tris is fine for a main character in a game nowadays, but you should only use that as a loose goal and use as many tri's as you need to define a good looking mesh, which is very subjective.

Main characters on console/pc will range from 30k to 200k this generation, depending on the game.

As for topology, you are going to have a pretty tough time, organic hard surface shapes are a pain in the ass to learn how to bake. Here are some rules of thumb to help you out.

1. Non-Destructively Triangulate your low poly model before you bake.
2. If you have a low poly edge that is >80° I recommend you chamfer that edge OR set a smoothing group/edge split there.
3. After you are finished UV mapping, before you bake, set your smoothing groups/split edges by your UV shells, there are scripts that do this automatically. Google is your friend.
4. Do a test bake very early on after you unwrap the parts, just use Auto-Uv Packing initially, when you are happy with the bake, then hand uv pack.

Hi,

I have finished my low poly game mesh. I deleted all the unnecessary pieces for easier unwrapping. Is it ready for uv mapping? Also, I don't understand your first and third rules. What is Non-Destructively Triangulate? and what do you mean "set smoothing groups by UV shells" ? Sorry, I'm a noob

ZacD

You probably want to clean up the intersecting cylinders on the upper arms. You have a lot of edge loops that aren't affecting the silhouette that could be removed or reduced.

Quack!

rayle1112 wrote: »

Hi,

I have finished my low poly game mesh. I deleted all the unnecessary pieces for easier unwrapping. Is it ready for uv mapping? Also, I don't understand your first and third rules. What is Non-Destructively Triangulate? and what do you mean "set smoothing groups by UV shells" ? Sorry, I'm a noob

Non-Destructively Triangulate

Before you bake you should force your mesh into triangles. You should do this non destructively because editing a quad model is much easier then a triangulated model.

I don't know how to do this in maya, but a quick google search on how to triangulate a mesh shows there is plenty of explanation. Just remember to make sure you aren't permanently triangulating your mesh.

set smoothing groups by UV shells

As you unwrap, you should make sure that you are correctly creating UV islands. At very harsh angles you should set a UV split, but your chamfers you have set, should allow you a bit more leeway. Try to bury your uv splits in crevices of your low or even at seam transitions in your high. This part is complex and requires quite a bit of practice, so over explanation won't be crazy helpful. This is why you should plan on 3-5 test bakes to make sure your normal maps are coming out correct.

rayle1112

Quack! wrote: »

Non-Destructively Triangulate

Before you bake you should force your mesh into triangles. You should do this non destructively because editing a quad model is much easier then a triangulated model.

I don't know how to do this in maya, but a quick google search on how to triangulate a mesh shows there is plenty of explanation. Just remember to make sure you aren't permanently triangulating your mesh.

set smoothing groups by UV shells

As you unwrap, you should make sure that you are correctly creating UV islands. At very harsh angles you should set a UV split, but your chamfers you have set, should allow you a bit more leeway. Try to bury your uv splits in crevices of your low or even at seam transitions in your high. This part is complex and requires quite a bit of practice, so over explanation won't be crazy helpful. This is why you should plan on 3-5 test bakes to make sure your normal maps are coming out correct.

I did a bake test and here is the result... I didn't do UV split, I just used auto-UV. So where is this issue coming from? my low mesh or auto-UV?

ZacD

Post your UVs and your high and low poly, it's hard to say what's going on without seeing everything.

rayle1112

It looks better after I add a custom cage and delete some edges of the low mesh.

rayle1112

Thanks everybody, I appreciate your time and effort to help me out!

I finally have finished this character. Check it out here! http://www.polycount.com/forum/showthread.php?p=2194944#post2194944