rgl (version 1.3.1)

planes3d: Add planes

Description

planes3d adds mathematical planes to a scene. Their intersection with the current bounding box will be drawn. clipplanes3d adds clipping planes to a scene.

Usage

planes3d(a, b = NULL, c = NULL, d = 0, ...)
clipplanes3d(a, b = NULL, c = NULL, d = 0)

Value

A shape ID of the planes or clipplanes object is returned invisibly.

Arguments

a, b, c

Coordinates of the normal to the plane. Any reasonable way of defining the coordinates is acceptable. See the function xyz.coords for details.

d

Coordinates of the "offset". See the details.

...

Material properties. See material3d for details.

Details

planes3d draws planes using the parametrization \(a x + b y + c z + d = 0\). Multiple planes may be specified by giving multiple values for any of a, b, c, d; the other values will be recycled as necessary.

clipplanes3d defines clipping planes using the same equations. Clipping planes suppress the display of other objects (or parts of them) in the subscene, based on their coordinates. Points (or parts of lines or surfaces) where the coordinates x, y, z satisfy \(a x + b y + c z + d < 0\) will be suppressed.

The number of clipping planes supported by the OpenGL driver is implementation dependent; use par3d("maxClipPlanes") to find the limit.

See Also

abclines3d for mathematical lines.

triangles3d or the corresponding functions for quadrilaterals may be used to draw sections of planes that do not adapt to the bounding box.

The example in subscene3d shows how to combine clipping planes to suppress complex shapes.

Examples

# Show regression plane with z as dependent variable

open3d()
x <- rnorm(100)
y <- rnorm(100)
z <- 0.2*x - 0.3*y + rnorm(100, sd = 0.3)
fit <- lm(z ~ x + y)
plot3d(x, y, z, type = "s", col = "red", size = 1)

coefs <- coef(fit)
a <- coefs["x"]
b <- coefs["y"]
c <- -1
d <- coefs["(Intercept)"]
planes3d(a, b, c, d, alpha = 0.5)

open3d()
ids <- plot3d(x, y, z, type = "s", col = "red", size = 1, forceClipregion = TRUE) 
oldid <- useSubscene3d(ids["clipregion"])
clipplanes3d(a, b, c, d)
useSubscene3d(oldid)