hello,
while trying to get the correct the user zoom changed by code (as Bruce
suggested),
I bounced into another problem, parallelism of up and forward.
Normally this problem won't occur, but switching between application,
made by different persons,
within the same scene (as I do right now) can cause this problem.
So I've made a convenience procedure to prevent the problem,
maybe some of you might benefit from it ,...
... or even have better (simpler) solutions.
cheers,
Stef
# ***********************************************************************
def Forward_Up ( Forward, Up ) :
"""
Sets both FORWARD and UP,
preventing temporary parallelism of FORWARD and UP
"""
# Be sure we've vectors
Forward = vector ( Forward )
Up = vector ( Up )
# Temp_Forward should not allign with
# 1. scene.up
# 2. Up
# 3. Forward
# And we may assume that Up and Forward don't allign
# The sum of Forward and Up, will fullfill conditions 2,3
Temp_Forward = Up + Forward
# calculate alfa, critical a=0 and alfa=pi
alfa = Temp_Forward.diff_angle ( scene.up )
# make alfa in range 0 .. pi/2, critical alfa = pi/2
alfa = abs ( alfa - pi/2 )
# make alfa in range pi/2 .. 0, critical alfa = 0
alfa = pi/2 - alfa
# if Temp_Forward alligned with current scene.up
if alfa < 0.1 :
# Create the product vector,
# which is perpendicular to Up and Forward (conditions 2,3)
# and will not allign with scene.up
Temp_Forward = dot ( Up, Forward )
scene.forward = Temp_Forward
scene.up = Up
scene.forward = Forward
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