Basic 3D

3D Point and Orthographic

Project a 3D point orthographically by keeping x and y and dropping z.

Example

Drop z to project a 3D point orthographically. Orthographic projection flattens a scene onto a plane by discarding depth, keeping the other coordinates unchanged so parallel lines stay parallel. Unlike perspective, distant objects are not shrunk, which makes this projection useful when true sizes and straight relationships must be preserved.

highlighted = computed this step

Step 1 — 3D point

Set up the exact input values.

P(2, 3, 4)\begin{array}{c|c}\text{P}&\text{(2, 3, 4)}\end{array}

Step 2 — Drop z

Compute the highlighted value.

dropped z4\begin{array}{c|c}\text{dropped z}&\hlmath{\text{4}}\end{array}

Step 3 — Screen point

Compute the highlighted value.

P prime(2, 3)\begin{array}{c|c}\text{P prime}&\hlmath{\text{(2, 3)}}\end{array}
Orthographic projectionThe projected point keeps x and y and drops z.P'
3d-point-and-orthographic Orthographic projection is the simplest 3D-to-2D projection: z does not change the screen location.