Lighting & rendering · Intermediate

Rasterization

The fast way games and viewports draw 3D, by filling in triangles on screen

What is rasterization?

Rasterization is the fast rendering method that projects each triangle of a 3D scene onto the screen and fills in the pixels it covers. Lighting, shadows and reflections are then added with shortcuts. It is how nearly every game, viewport and real-time app draws its frames.

Think of it like this

It is like filling in a mosaic: for each shape, you color every tile it covers, then move on to the next shape.

Where it fits in a 3D project

  1. Create
  2. Surface
  3. Rig
  4. Animate
  5. Render
  6. Export

Render: Lighting the scene and turning it into images or video.

3D trianglePixels it covers get filled
Rasterization projects each triangle onto the screen and fills the pixels it covers.

How rasterization works

  1. 01The scene’s triangles are projected from 3D onto the flat screen.
  2. 02Each triangle is split into the pixels it covers.
  3. 03A shader colors each pixel using materials, lights and textures.
  4. 04A depth buffer keeps only the surface nearest the camera at each pixel.

Rasterization vs ray tracing

PropertyRasterizationRay tracing
Starts fromThe scene’s trianglesRays sent from the camera
SpeedMany frames per secondSlower per frame
Reflections and shadowsApproximated with tricksCalculated from the scene
Typical useGames, viewports, appsFilm, product shots, high-end effects

Rasterization wins when the image must update instantly; ray tracing wins when lighting must be accurate. Many modern engines rasterize first and add ray-traced effects on top.

Where rasterization is used

  • Video games and interactive apps
  • The 3D viewport you model in
  • Web and mobile 3D viewers
  • AR and VR, where frames must arrive fast

Beginner tip

If a real-time scene looks flat, the fix is usually lighting tricks such as baked lightmaps and ambient occlusion, rather than more polygons.

Terms related to rasterization

Rasterization FAQ

Why do games use rasterization?
Speed. A game must draw a new frame many times a second, and graphics cards are built to rasterize triangles very quickly. Ray tracing every pixel is still too costly for most hardware at that rate.
Is rasterization still used now that ray tracing exists?
Yes. Rasterization still draws most of every real-time frame. Ray tracing is usually added only for chosen effects, such as reflections or shadows, on top of a rasterized image.
Does Blender use rasterization?
Yes. Blender’s viewport and its real-time render engine rasterize, while its main photoreal engine path traces. Many artists preview with the first and render final frames with the second.

Updated October 29, 2026 · Browse all 3D terms