Project world coordinates to image pixels

Runs the same view and projection as the renderer, so the result lands exactly on the rendered image. Useful to place screen-space annotations (text_layer(space = "screen")) next to a 3D location, or to draw callout lines with line_layer in image coordinates.

Usage

world_to_screen(points, camera, width, height, options = NULL)

Arguments

points

An Nx3 numeric matrix of world coordinates (or a length-3 vector for a single point).

camera

A camera list from camera() or camera_auto().

width, height

Size of the rendered image in pixels.

options

Render options, used for the projection type and the clipping planes. NULL uses default options with the given size.

Value

A data frame with one row per input point and the columns x, y (pixels, origin top left), depth (NDC depth, smaller is closer) and in_front (whether the point is in front of the camera; for FALSE the pixel coordinates are not meaningful).

See also

text_layer

Examples

sph <- generate_sphere(c(0, 0, 0), radius = 1)
cam <- camera_auto(list(sph), direction = c(0, 0, 1))
opts <- render_options(width = 400, height = 300)
world_to_screen(matrix(c(0, 1, 0), ncol = 3), cam, 400, 300, opts)
#>     x        y     depth in_front
#> 1 200 75.42025 0.9588302     TRUE