Unity‐chan Costume Tutorial
In this tutorial, we will fit the Unity-Chan! Sunny Side Up model for use on female characters.
By the end of this tutorial, this what we will have in-game as a Cobalt mod.
You will need to have these programs installed.
- Blender, for the 3D modeling portion.
- Robust Weight Transfer, a Blender plugin, for the 3D modeling portion.
- Unity, for the building portion.
- [something] for the Material editing portion.
- An Engage female base body.
- The Unity Chan costume files.
- Mod bootstrap files
Open the Engage female base body file by double-clicking on it.
This is what it should look like right after it opens in Blender.
You can orbit the camera by clicking the middle mouse button and moving the mouse.
You can pan the camera by pressing the shift key and then clicking the middle mouse button, and moving the mouse.
You can zoom in and out by scrolling the mouse wheel.
In the upper right corner, you should see a few colored circles. This is called the Navigation Gizmo. Click on the colored circles with letters on them, to quickly change viewing angles and snap to side and top views.
Drag-and-drop the unity chan FBX you downloaded into Blender.
You should see a dialog box that looks like this. Leave everything set at their defaults. Click Import FBX.
You will notice that Unity chan drops right on top of the base body. Additionally, a few items are highlighted in the side panel in bright orange. Those are the objects that we just imported.
This are a bit messy, so we will start by hiding the Engage base body. Move your mouse over the Eye icon next to the base body in the side panel.
Shift click it to hide it and everything underneath it.
You will notice that only Unity chan is left in the viewport. If this is not the case, make sure you shift-clicked the eye next to uBody_Base0AF_c000, and not the camera.
Click on the little arrow next to Character1_Reference
You should see something like this in the side panel.
There are a lot of objects here, but we will be working with the Shirt first.
Shift click on the eye for Character1_Reference to hide everything, then click the eye for just the Shirt to bring it back.
Now scroll down in the side panel to the bottom, and click the eye next to uBody_Base0AF_c000_Skin.
Your viewport should look like this now, with only the body and the shirt showing.
The shirt isn't a great fit right now. It's a floating over the base body, and is a bit big.
Move your mouse over to the Navigation Gizmo the click the green circle until you're looking at the model straight on. It should show -Y.
Now, select the Shirt by left clicking on it in the viewport. Notice that is it highlighted in orange, and the line saying Shirt is also highlighted in the side panel.
In Blender, we can move objects by pressing the G key, and then moving the mouse. To remember this, we can think of G as standing for Grab.
Now, press the G key. Notice that the orange highlight is now white. Try to move it down a bit, so the shirt on the body.
It's tricky to move things in a straight line, so press Z key while the object is still being moved. You will see a blue line like this.
If you move the mouse now, the movement will be constrained to the Z axis (up and down). This allows us to move the shirt while keeping it centered. The same feature is available with Y and Z for the corresponding axes.
When you get the shirt fitting over her shoulders, click the mouse button to confirm the move. Notice that the highlight is orange again.
If you don't like where you put the shirt, you can use control Z to undo, or G to move it again.
The scene should look something like this now.
Let's check how well the costume is fitting now. Use the Navigation Gizmo and the middle mouse button to check out our work.
While the shirt is in a better position, it seems a bit big right now still.
In Blender, we can scale objects by pressing the S key, and then moving the mouse. To remember this, we can think of S as standing for Scale.
With the shirt still selected, press the S key and move your mouse, the click to confirm the scaling.. You will notice that it is getting smaller, but is also moving in a strange way. That is because the origin point for this object is somewhere down near the ground.
In the menu, choose (the option for this)(Origin to Geometry). This will move the origin to a more sensible place.
Now try using the S key again, and scale the shirt to fit better. You can also move it with G if you need to.
The shirt should look something like this now. Don't worry that the shirt isn't perfectly covering her torso, because the hoodie covers the rest of the upper body. We will come back to finish adjustments to the shirt later.
Use the eye icon and hide the shirt and show the hoodie and the zipper.
The hoodie isn't a great fit right now. It's a floating over the base body, and is a bit big in certain parts.
Select the hoodie the G key to move the costume into a better place. However, notice that the zipper didn't move along with the costume. This is because they are two separate objects.
Undo the move. We can shift click the two objects to move them together at the same time.
Try this now by first clicking on the Zipper, and then shift clicking on the Hoodie. Now, use the G key to move.
The two objects now move together.
However, since we will be continuing to work with these two objects, we will join them so that they are one object.
To do that, we select the two items and then join them with control-J.
The order we select objects can change the results of certain operations, including join.
To see the difference, we will try joining two ways.
First select Hoodie, then shift click and select Zipper. Notice the colors here: Hoodie is orange, and zipper is yellow and higlighted in blue. Now, press control-J. The objects are joined and only the Zipper object remains.
Now undo the join with control-z. This time, select the Zipper first, and then select the Hoodie. Notice the colors here and how they are different from last time. Join the objects, and you will be left with Hoodie.
We will proceed with this join as calling this object Hoodie makes more sense.
You should end up with something like this.
Adjust Hoodie to be in a better position with G.
Notice that the base body is clipping out a bit in the rear. However, if we try to move the hoodie to fix this, other parts will now clip, so just moving it isn't enough to make it fit better - we will need to edit the shape of the hoodie to better match the base body.
In the upper left corner, there is a button that looks like (this). Object mode is used to manipulate objects as a whole, and edit mode is used to edit the vertices that make up the object.
Make sure that the hoodie is selected, and click on Object Mode, then select Edit mode.
The view will look like this now. If it doesn't, double check that you weren't selecting the base body when switching to object mode.
The same G key we used to move the hoodie as an object, can be used to move the hoodie vertices as well.
Select a vertex like this (it doesn't need to be this precise one, any in the area will be OK) and then use G to move it. Notice that now the shape of the hoodie changes when you move your mouse.
This is a step in the right direction, but there are many vertices and it would take a lot of time to move each one of the individually.
Esc to cancel this change for now.
In the upper (bar), there is a tool called (proportional something). Click on it. Now, select the same vertex as before by clicking on it, and move it again with G. Scroll your mouse wheel, and you will see a circle changing sizes. This is the sphere of influence for the proportional something. You can try moving it around to get a feel for it.
Once you find a good place, click to confirm it.
Your costume should look something like this now. Use the camera controls to take a look at our work.
Notice that while we fixed one side of the hoodie, the other side is still sticking out. While we could use the same method we did just above, again, there is a better way.
Undo this change with control-Z.
The Unity-chan costume was created in a way that is mirrored, meaning the left and right sides are symmetrical with the same vertices, just flipped.
Use (this button) to turn on symmetry for the X axis.
Now, we can try to fix the clipping again. Click on one on the vertices with proportional editing on, and use the G key.
You will notice that the opposite side moves together now.
Place it in a position like this and confirm it.
The sides here are a little loose.
We will select multiple vertices to move together to keep their shape.
You can select multiple vertices by drawing a box around a few of vertices. If this doesn't work for you, check that you have the (tool) selected on the left hand side.
With a few vertices selected, use the G key to move the vertices into place like this. If it looks like the hoodie is getting jagged, make sure proportional scaling is on.
You can use the A key to select all vertices and move the entire hoodie. Use this to reposition the hoodie a bit. You can press A twice in quick succession to deselect.
Try to get your hoodie looking something like this, and we will be ready for the next step.
Now, turn on the shirt again. You may notice that it clips out of the hoodie in some places. To edit the mesh for an object, you must first chose Object mode, then click the piece you want, then click edit mode.
Using the techniques we went over above, get the shirt fitting something like this and to your liking. If you want to edit the hoodie, you can switch back to the hoodie to edit that to your liking. If the hoodie is in your way, you can hide it with the eye button temporarily.
At the end, the shirt and the hoodie should look something like this.
By the end of this section, we will be able to play an animation with our costume on the character to check how well it is fitting.
First, we need to select the bones for body. Then, click the Data button (it looks like a little green person). Then, choose Pose position.
After this, go and choose Action Editor, and in this dropdown, choose (animation name).
Now, by scrubbing the Timeline in the action editor, we can see the character moving.
And, we will see that the costume is not moving with the body, but is just floating in place.
So, although the body moves, the clothing pieces does not.
A few things are needed before clothing pieces will move with the body.
Here's some explanation about what will be happening next, but you can skip ahead if you just want to get things working.
Click on the Skin object, and then the blue wrench. These are the modifiers. Notice that there is a modifier here Armature. It tells the skin object that it should react to the bones in Object if they move.
Now click on the green triangle with squares. These are the vertex groups. Notice that the if you flip open the bones, you will see the same names as list of names in the vertex group. Click on the skin, then switch to Weight Paint mode. You will see the body turns blue. Now, click on [vertex group name]. Notice how those areas light up in a gradient of colors. These are the vertices that will move with that bone.
If you check the weight painting for the Hoodie or Shirt, you will see that it has none.
These two pieces - the modifier, and the weight paint are both required for our costume to move.
Select the Hoodie and go to the modifier tab, and add the modifier. Do the same for the shirt.
We now have the armatures set up.
We will reuse the weights that the body has.
First, we need to set the body back to Rest pose.
Find the SENT tab and click it, then open Robust Weight Transfer.
For the source, choose skin.
Then, select the Hoodie and click Transfer Weights. If this button is grayed out, make sure you are in Object mode, and not edit mode.
Do the same for the shirt.
Now, select the bones again and choose pose mode.
The costume now moves with the body as you scrub through the timeline.
Go to weight paint mode, and notice that the hoodie now has weight painting as well.
Now, let's work on fitting the shorts.
Hide everything except the LowerBody for now.
Notice that the LowerBody itself has skin from the Unity-chan costume itself. Since we have an Engage base skin already, we will cut out the shorts for use in our costume.
Select the LowerBody and choose Edit mode. Alt/option click on this edge which is the visual boundary between the shorts and the leg. This selects the ring that forms the leg hole of the shorts. Use G to check that you've selected this correctly. If your selection doesn't move like this, make sure that you did not deselect it.
To separate the shorts from the leg skin, we can use the Rip tool. With the ring still selected, press V, and then enter to confirm. Using G now, try moving the selected ring. You'll notice that the shorts and the skin are no longer joined.
We need to do this again to the other short leg.
With that done, we will now separate the shorts section into its own object.
Press A twice quickly to deselect everything. Then, hover your mouse over the shorts and press L for the Select Linked tool.
You should see the shorts highlighted and nothing else. If you see the shorts and a leg or two selected, makes sure you've ripped the boundary between the shorts and the leg correctly.
Now, press P, and choose Selection. Notice that we now have a LowerBody and and LowerBody.001 object in the outliner.
Switch to Object mode, and click .001. Double click on it and rename it to Shorts, then press Enter to confirm.
Hide the remaining LowerBody for now, and then using the techniques we discussed above, we will fit the pants so that they look right.
Your window should look something like this now. Notice how no matter how we place the shorts, there will always be some parts that clip into the body, making it hard to select vertices to move them.
We can use the X-Ray tool to help here.
Click the X-Ray tool in the upper (whenever). Notice that we can now see a slightly greyed out outline of the shorts. You will also be able to click through the body to edit the vertices.
For an easier view of what is going on, switch to the Solid shading mode. You can adjust the amount of transparency to your liking here.
Change the color of the shorts here to make things easier to see.
After you get the shorts in a decent position, give it an armature modifier and weight transfer as we did before.
Don't worry too much if the pants look a little weird in the animations - it will be mostly covered by the hoodie anyway.
You should have something that looks like this with the shirt, hoodie, and pants.
We will be preparing our costume to try in the game next.
If you haven't already, set up Unity using the guide described here.
Introduction to the Divine Dragon Build tool. Talk about the setup needed to build a model bundle, assigning materials, addressables
Show the needed item xml line.
Show the relation between the MSBT and the XML fields.
Possibly out of scope, and should be already created for the user. A separate "how to guide" may be more appropriate for multi-creation.