While the 60s were about proving that computers could draw, the 1970s were about teaching them to understand volume, depth, and texture. It was the decade where computer graphics moved from simple 2D lines to complex 3D surfaces. The hardware was still incredibly slow by modern standards, so computer scientists had to rely on brilliant mathematical shortcuts and algorithms to fake reality.
1972 - Ed Catmull’s Animated Hand
Before he founded Pixar, Ed Catmull was a student at the University of Utah (the Silicon Valley of graphics at the time). In 1972, he created one of the world's first 3D rendered movies: A Computer Animated Hand.
He drew polygons on his own hand with a marker, measured the coordinates, and input them manually into the computer. This short film showcased smooth shading and movement years before "Star Wars" existed. It proved that organic shapes could be digitized—a crucial step for future bioprinting and character design.
1975 - The Utah Teapot
If 3D graphics has a mascot, it is the Utah Teapot. Created by researcher Martin Newell, this object became the standard test model for rendering algorithms. But why a teapot?
- Topology: It is round, has a hole (the handle), a lid, and a spout.
- Self-Shadowing: It allowed programmers to test if the spout cast a shadow on the body.
- Realism: It was a familiar household object (a Melitta teapot), making it easy to judge if it looked "real."
Even today, you can find the Utah Teapot hidden in famous movies like Toy Story and The Simpsons, or built-in as a primitive in software like 3ds Max.
The Birth of Solid Modeling (CSG)
This is arguably the most important development for 3D printing. In the early days, 3D models were just "surfaces" or empty shells (like a balloon). But to manufacture a real object, the computer needs to know it is solid inside.
This led to Constructive Solid Geometry (CSG). It is the math of combining simple shapes to create complex ones using Boolean operations:
- Union: Fusing two shapes together.
- Difference: Using one shape to cut a hole in another.
- Intersection: Keeping only the overlapping part.
When you use the "Hole" tool in TinkerCAD or "Combine" in Fusion 360 today, you are using the CSG logic developed in the 1970s. Without CSG, 3D printers wouldn't know the difference between a solid wall and a ghost image.
Shading the World: Gouraud & Phong
To make 3D objects look real on a flat screen, they needed to
reflect light. Two major shading techniques were invented in this
era:
Gouraud Shading (1971): Smoothed out the sharp
edges of polygons.
Phong Shading (1973): Added realistic specular
highlights (the shiny white spot on a plastic ball).
These algorithms allowed designers to visualize the "surface finish" of a product before it was ever manufactured, bridging the gap between digital design and physical reality.