fGetTransformedCoordinates: Function to easily transform coordinate spaces

In thecomeonman/POV: 3D transformations

Function to easily transform coordinate spaces

Description

Function to easily transform coordinate spaces

Usage

fGetTransformedCoordinates(
  mCoordinates,
  mOriginCoordinates,
  mScreenCoordinates,
  mViewBeginsFromCoordinates = NULL,
  mVectorPointingUpOnScreen = c(0, 0, 1),
  iTreatAs = 3
)

Arguments

mCoordinates	matrix with three columns [x,y,z] with >= one rows
mOriginCoordinates	three column, one row matrix specifying coordinates of where the scene is being viewed from
mScreenCoordinates	three column, one row matrix specifying coordinates of the screen on which the scene is being projected on. The function calculates a plane which is perpendicular to the vector from mOriginCoordinates to mScreenCoordinates which contains mScreenCoordinates. This plane is the screen on which things are projected finally.
mViewBeginsFromCoordinates	if NULL, all objects in front of origin, where front is the direciton in which the screen coordinates are, are projected. If a set of coordinates is given then all objects in front of that coordinate, where front is the direciton in which the screen coordinates are, are retained, and other objects are treated as behind the view. If this coordinate is on the opposite side of the origin as the screen then you'll delete all objects and get an empty array in the results. This dividing plane and iTreatAs together also affect how points are treated when data is crossing the dividing plane. Points behind the dividing plane are just deleted but paths / polygons get an interpolated coordinate on the dividing plane which helps retain a continuity to the data when plotted
mVectorPointingUpOnScreen	Which way is up for the viewer
iTreatAs	1 for isolated points, 2 for path, 3 for polygon. This matters if you have data going behind the mOriginCoordinates / mViewBeginsFromCoordinates as explained in mViewBeginsFromCoordinates.

Value

If inputs are valid, a matrix with 2 columns for the x,y coordinates on the screen, an optional column, group: linking continuous stretches in front of the screening plane which can be used in geom_path(aes(group = group)), an optional column inputOrder: which lets you map the output back to the data that was sent in. If invalid inputs then you'll get a NULL.

thecomeonman/POV documentation built on Sept. 24, 2022, 8:31 p.m.