[Introduction to Blender] Let’s Make Clothes with Cross Simulation (Basics – Preparation)

Monday November 1st, 2021

Have you ever heard of cloth simulation?
Cloth simulation is useful when making clothes in Blender. Let’s try to make a simple shirt with this function.
I’ll show you how to make it in two parts, as follows!

Basics – Preparation (How cross-simulation works and how to prepare for shirt modeling)
Production – Simulation section (from shirt modeling to simulation)

Blender version used: 2.93.1

1 What is cloth simulation?
2 How does cross simulation work?
3 Creating a Shirt
- 3.1 Prepare the model to be dressed.

What is cloth simulation?

As the name “Cloth Simulation” suggests, it is a function that performs physical operations on cloth.
By using cloth simulation, you can create realistic models with movement, such as wrinkles on clothes when people move, or flags flapping in the strong wind.

This function can be used not only in Blender but also in most CG software.

How does cross simulation work?

In the real world, there are various physical laws such as gravity.
To reproduce them in CG software (in this case, Blender), we need to prepare models for cloth and obstacles, and assign physics to each of them.

Preparing models for cloth and obstacles

Plane with crosses assigned and Suzanne & Cube with collision assigned

(For clarity, only the angle of the red model has been slightly changed to make it asymmetric)

Add a model for the obstacle

Press [Shift+A] to add a cube mesh

Click to select → [S] key, move the cursor to zoom in → click again to confirm / [S] key → [Z] key to change only the height

Deselect the cube and press [Shift+A] key to add a monkey.

Add a monkey

Select → [G] key → [Z] key to move in Z direction → Click or Enter key to confirm

Add a model for cloth

[Shift+A] key to add a new plane

Press [G]→[Z] key to move to Z direction, press enter to confirm / [S]→move cursor to zoom in, press enter to confirm

It looks like we are ready to go, but if we don’t, there is only one plane and the cross-simulation will not work properly.

We need to subdivide the plane.

So, let’s subdivide it so that the plane will move smoothly.

Select a plane and switch to edit mode by pressing the [Tab] key.

Change to edit mode by pressing the [Tab] key (or the upper left button) while in object mode.

Switched to edit mode

Then, right-click to bring up the menu, and select Subdivide.

Select Subdivide from the menu that appears when you right-click.

Right-click -> Subdivide to subdivide, and click or enter to confirm.

In this case, we are subdividing twice.
The more times you subdivide, the smoother the cross simulation will be, but the slower it will be, so be careful.

Assigning Cloth and Collision

Assign crosses to the prepared planes and collisions to the other monkeys and cubes.
To assign them, simply click on the model and select one of the simulations from the properties on the right.

Select the model -> tool icon -> modifier -> select Cross or Collision

You can also assign a simulation from the Physics tab.

Playing the animation

Click on the Play button at the bottom center of the screen to play the animation.
The model (cross) will automatically fall on top of the other model (collision).
If it slips through cubes, etc., check if the collision is properly reflected.