🟠Learn how to create proper UVs for a human character, backpacks, and add-ons in this step-by-step tutorial using Autodesk Maya and ZBrush.
🟠Optimize UV layout and export for Substance Painter.
- Workflow
Today we’ll be cutting UVs for a Soldier character and going through the workflow of how to open up UVs for clothes and for a human body.
Open up ZbBrush and from the LightBox inside the Projects folder double click on the Demo Soldier.
The character comes with divisions and with clothes.
We want to lower the divisions with Shift + D so our active points reach around 2k.
After that, go to the Zplugin tab, FBX ExportImport, and Export the Demo Soldier, making sure it is set on All.
Open up Autodesk Maya and drag and drop the FBX file inside your workspace.
When we select the model we can see that there are no UVs.
Create a Planar UV as a start.
The first thing we’re going to cut is the arms.
Make sure you have Symmetry turned on on World X.
Cut the shoulders to separate the arms from the body.
Cut the wrists to separate the hand from the arm.
Afterward, just cut the entire arm and hand in half.
For the head, we’re going to separate it from the body u cutting it near the neck and the shoulders.
Cut the face so it’s a separate UV shell.
Cut the inside of the mouth.
Cut the ear from the body and separate the front of the neck from the back by cutting its own UV Shell.
When we unfold the face we can see that the texel density is the same throughout the head which is what we aim to achieve when we cut UVs.
Cut the legs away from the torso and make a cut on the side of the torso to split it in half.
Split the legs in half as well with one big edge loop.
Make a cut at the ankles of the foot and around the foot itself.
Sew back the edges that are splitting the bottom of the foot into two parts.
Now when we Unflod and Layout our shells we can see that the texles density is the same all around.
Just like with the barrel, we can stack similar UV shells on top of each other.
The downside to this is that we won’t be able to texture one arm or leg differently if the UVs are stacked on top of each other.
Shift + click on the Layout tool to open the Layout Uvs Options.
In here tick the Stack Similar box in the Pack Settings.
If we select all the UVs and try to Lay them out the stack similar won’t work.
We have to first flip one of the similar UV shells by holding down Shift + Right click and choose the Flip Along U.
After the UV shell has been flipped if we select the other one and lay it out then the Stack Similar will apply.
Do this to the other similar UVs and Lay them out.
We won’t go through all of the clothes and accessories on the model and only cut UV shells for the backpack.
The rest of the clothes and accessories are for personal exercise after reading through the class.
Cut the inside of the backpack.
Make cuts on the top and bottom of the straps.
Unfold and Layout the UV shells and as we can see the inside of the backpack won’t be seen on the character.
We’re going the select the UV shell from the UV grid that is the inside of the backpack and delete them from there.
We’re still going to have the faces on the backpack but not the UV shells.
We can transfer these UVs that we created in Autodesk Maya to Zbrush.
There are two ways we can do that.
Export only the body of the character, one as an OBJ and one as an FBX file.
Inside of Zbrush import the FBX file first.
Doing this will create a new PolyMesh3D of our character’s body.
Inside the Zplugin tab, open UV Master and Copy the UVs.
Go back to the Demo Soldier we exported from the beginning and make sure that the body is in the same division as the one we cut the UVs on.
Select the body, go to Zplugin, UV Master, and Paste the UVs.
Now the Demo Soldier with divisions has UVs on it.
We can check if something has UVs if we go into the UV Map options and see that the Morph UV button is active and pressable.
The second way we can add already-made UVs inside Zbrush is through the OBJ file.
First, delete the UVs that were added to our soldier through the UV Map options, there is a button that says Delete UV.
Again make sure that the divisions are down to the same number of active points as the body we cut the UVs on.
Now import the OBJ file in the project at first it will seem like nothing has happened but actually, the OBJ file over-wrote the body file in the Demo Soldier.
When we click on the Morph UV button it will unwrap the UV on the mesh we have selected and that has UVs.
Another way to make UVs is inside ZBrush itself.
Select the body, open the Zplugin tab, go inside UV Master, and click on the Unwrap button with Symmetry turned on.
After the software is done processing the command when we click on the Morph UV we can see that it has indeed made a UV for the body.
If we add polygroups onto the body, separating all the parts like we did when we cut UVs for the body inside of Autodesk Maya, and this time Unwrap the body also having the Polygroups option on it will unwrap the polygroups and make them their own UV Shells.
Bonus - Inside Meshes
To make a model game ready it is important for the model to have good retopology but also it is just as important to remove any polygons or faces that won’t be visible on the model at all because of them being covered.
In this bonus, you will learn how to get rid of inside meshes using ZBrush.
We’ll use the Demo Soldier ZBrush project for this example.
The glove on the character has polygons inside the glove itself, these polygons won’t ever be seen by the viewer and are only taking up unnecessary space.
To get rid of these polygons we’ll use the ZModeler Brush (BZM).
Hold space on top of a polygon to open the Polygon Actions.
From there set the Action to Delete and the Target to Polyloop.
Start deleting the poly loops around the edges of the gaps on the glove.
Once you separate the outside and inside of the glove, go into the Polygroups tab and click the Auto Groups button.
Now the inside and outside of the glove are two separate polygroups.
Ctrl + Shift click the top of the glove to isolate it from the inside faces, go into the Geometry tab, Modify topology and click the Del Hidden button to delete the inside polygroup so only the outside remains.
This is how a game-ready glove should look on a character, not having any faces on the inside where the hand is going to be.