3.14 or Pi? a Multi-Angle Optical Illusion in Fusion 360

Have you ever seen a number turn into a symbol just by changing your point of view?

In this project, I designed a 3D object that looks like “3.14” from the front, but magically becomes “Pi” from the side. And from the top? A hidden π symbol appears through a cut-out.

This project combines 3D modeling, perspective design, and a bit of visual illusion all made in Fusion 360.

Fusion 360, Computer, access to a computer.

I started by sketching the number 3.14 on a front plane in Fusion 360.

Then, I extruded the sketch to give it thickness. This created the base structure that defines how the object will look from the front.

💡 The key idea:

The front view must remain clean and readable no matter what modifications are added later.

This step required careful adjustment.

I had to ensure that:

1. The front view still clearly shows 3.14
2. The side cut clearly forms Pi
3. The structure remains physically possible (not too fragile)

This part involved tweaking alignment, spacing, and thickness.

Creating a third readable view was more challenging.

Instead of modifying the main structure too much, I designed a base platform.

On the top face of this base, I created a cut-out of the π symbol.

From above, this reveals a clean and recognizable π shape like a hidden layer of the design.

From different angles, the object reveals different meanings:

1. Front → 3.14
2. Side → Pi
3. Top → π symbol

This project shows how perspective can completely change perception.

💡 What I Learned

1. How to design for multiple viewpoints
2. Using boolean cuts creatively
3. Balancing structure and readability
4. Thinking in 3D, not just shapes