Recipe: refaxis

created by bob1928

Profile

• Name: refaxis
• ID: 48212
• Shared with: Public
• Parent: None
• Children: None
• Created on: February 14, 2014 at 17:43 PM UTC
• Updated on: February 14, 2014 at 17:43 PM UTC
• Description:

  creates axes as reference markers

Code

--[[
Creates Axes for Reference

Attaches a set of disabled bands to segment 1
as visual reference marks. Since these are
referenced to segment 1, 2, and 3 the orientation
can change as those segments are rebuilt.

The first angle argument (theta) is "angle from
zenith" (like latitude, but 0 is north pole, pi/2
(90 deg) is equator, pi (180 deg) is south pole).

The Z axis is longer and thicker. X and Y follow
a "Right Hand" convention (as the fingers of the
right hand curl from X toward Y, the thumb points
to Z.)

The second angle argument, Phi, is measured from X,
going positive toward Y (just like longitude).


]]--
function refaxis()
    axisbands={}
    local theta=math.pi/2
    axisbands[1]=band.Add(1,2,3,10,theta,0)
    axisbands[2]=band.Add(1,2,3,10,theta,theta)
    axisbands[3]=band.Add(1,2,3,15,0,0)
    for idx=1,3 do
        band.Disable(axisbands[idx])
    end
    band.SetStrength(axisbands[3],5)
end
refaxis()

Comments

[bob1928]

Attaches a set of disabled bands to segment 1
as visual reference marks. Since these are
referenced to segment 1, 2, and 3 the orientation
can change as those segments are rebuilt.

The first angle argument (theta) in the code is
"angle from zenith" (like latitude, but 0 is north pole,
pi/2 (90 deg) is equator, pi (180 deg) is south pole).

The Z axis is longer and thicker. X and Y follow
a "Right Hand" convention (as the fingers of the
right hand curl from X toward Y, the thumb points
to Z.)

These are visual reference marks only. They are not
universal and serve no purpose in setting or
reading positions.

The second angle argument (last entry in the band.Add
commands) is usually know as Phi. It is measured going
around Z and is positive going from X toward Y, just
like longitude.