Building Games in 3D

A reference for the rendering, simulation, and presentation systems behind real-time 3D.

The Rendering Pipeline

Geometry travels through a fixed sequence on its way to the screen:

vertices  →  transform & project    (vertex stage)
          →  fill triangles to a grid   (rasterization)
          →  shade each covered pixel   (fragment stage)
          →  composite to the framebuffer  (output)

Cut work before it reaches the GPU:

Shaders

Reach for a custom shader when you need:

• A bespoke effect the standard material cannot produce — flowing water, flickering fire, a swirling portal.
• A deliberate art direction such as cel-shading or a hand-drawn sketch look.
• A faster path than the default lighting for a specific case.
• A signature look that sets the title apart visually.

Physics in 3D

Guiding rules:

• Pair a lightweight collider with the detailed visual mesh; never collide against the render geometry directly.
• Route interactions through collision layers so unrelated objects ignore each other.
• Use raycasts for sightlines, hit-scan weapons, and ground checks.

Cameras

What makes a camera feel good:

• Lerp toward the target instead of teleporting to it.
• Push in when geometry would otherwise clip through the lens (collision avoidance).
• Lead the view slightly toward motion (look-ahead).
• Widen the field of view at speed to amplify the sense of velocity.

Lighting

Cost-aware shadowing:

• Dynamic shadows are expensive — budget them carefully.
• Bake lighting and shadows into textures wherever the scene is static.
• Split shadow detail by distance with cascades across large outdoor maps.

Level of Detail

Swap models by how far they are from the camera:

Mistakes to Avoid

Bottom line: 3D is a magic trick — sell the impression of detail rather than rendering all of it.