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Old 05-19-2010, 04:24 AM
Saz Saz is offline
Join Date: Nov 2008
Posts: 36
random speed and associated coding

Hi there,

I want the code to sample a random accelerator gain from a predetermined list, but when the gain changes, the coding for the indicated speed in mph also has to change, to give the correct speed in the text box.

I put this together so far
import viz
#Import vizjoy module
import vizjoy  
import time
import math
import vizact
import vizinfo
import random

viz.displaymode(1024, 768)
vizact.ontimer(40,viz.quit) #runs file for 40 secs

subject = viz.input('What is the participant number?')

MOVE_SPEED = 0.25 #initial speed scalar
#define random speed scalar constant for changing gain on accelerator

#Add a joystick 
joy = vizjoy.add() 


sky = viz.add(viz.ENVIRONMENT_MAP,'sky.jpg')

skybox = viz.add('skydome.dlc')

#add the road texture
road = viz.add('roadld3.png')
#road2 = viz.add('roadsd.png')

#add the ground
ground = viz.add('tut_ground.wrl')

#create a texture quad to add the road texture to
#and place it over ground
quad = viz.addTexQuad()

road_position = 0
ground_position = 50
#add road and ground if getting near the end of road
def addRoad():
	global road_position, ground_position
	viewpoint_pos = viz.MainView.getPosition()
	#check to see how close the viewpoint is to the end of the road
	if road_position - viewpoint_pos[2] < 50:
		#add 50 meters of ground
		global ground_position
		groundcopy = ground.copy()
		ground_position +=50
		#add 50 meters of road
		for i in range(1,50):
			quadcopy = quad.copy()
			road_position +=1

#call a timer every frame to check if road needs to be added
vizact.ontimer(0, addRoad)

#change the road texture on keypress
#vizact.onkeydown('1', quad.texture,road2)
#vizact.onkeydown('2', quad.texture,road)
vizact.onmousedown(viz.MOUSEBUTTON_LEFT, quad.texture,road)
#vizact.onmousedown(viz.MOUSEBUTTON_LEFT, quad.texture,road2)

def UpdateJoystick():
    #Get the joystick position
    x,y,z = joy.getPosition()
    #Get the twist of the joystick
    #twist = joy.getTwist()
    #Move the viewpoint forward/backward based on y-axis value
    if abs(y) > 0.0001: #Make sure value is above a certain threshold
    #Move the viewpoint left/right based on x-axis value
    if abs(x) > 0.001: #Make sure value is above a certain threshold
    #Turn the viewpoint left/right based on twist value
    #if abs(twist) > 0.001: #Make sure value is above a certain threshold
    #    viz.MainView.rotate(0,1,0,twist,viz.BODY_ORI,viz.RELATIVE_WORLD)

#UpdateJoystick every frame

#define random speed scalar constant for changing gain on accelerator
	global MOVE_SPEED, speedm, speedcon
	MOVE_SPEED = random.choice([0.15,0.2,0.25,0.3])
vizact.ontimer(5, MOVE_SPEEDSC)

#add textbox and set position on screen
text_speed = viz.addTextbox(parent = viz.SCREEN)
text_speed.setPosition(.15, .9 ) 
text_speed.fontSize (30)

old_posZ = 0
def showSpeed():
	global old_posZ, speed, speedm, speedcon 
	current_pos = viz.MainView.getPosition()
	current_posZ = current_pos[2]
	distance = abs(current_posZ - old_posZ)
	#get speed in meters/sec
	speed = (distance/viz.elapsed())
	#get speed in mph
	#speedm = 4*(speed*3600)/1609.3
	#chnage multiplier to reflect gain change
	if MOVE_SPEED == 0.15:
	speedm = 4*(speed*3600)/1609.3
		speedm = 6.666666667*(speed*3600)/1609.3
	if MOVE_SPEED == 0.2:
		speedm = 5*(speed*3600)/1609.3
	if MOVE_SPEED == 0.25:
			speedm = 4*(speed*3600)/1609.3
	if MOVE_SPEED == 0.3:
		speedm = 3.33333333*(speed*3600)/1609.3

	old_posZ = current_posZ
	#enter speed in textbox rounded to 1 digit after decimal
	text_speed.message(str(round(speedm,1))+ 'MPH')
vizact.ontimer(0.25, showSpeed)

#Open file in path

filename = 'gainchangeprac_.txt' + str(subject)
def getPublishedPath(filename):
	#filename = 'adapt_.txt' + str(subject)
	publishPath = viz.getOption('Y:\backup\Vizard30\resources\road\_.txt','')
	if publishPath:
		return '/'.join([publishPath,filename])
	return filename

file = open(viz.res.getPublishedPath(filename), 'w')

def mytimer (num):
	#joy_pos = str(joy.getPosition())
	out = (str(round(speedm,1)) + '\n')
	print out
viz.callback( viz.TIMER_EVENT, mytimer )
viz.starttimer( 0, 0.25, viz.FOREVER ) #capturing 4 times a sec
And it all appears to be working ok, but is difficult to verify for sure. Would you be able to cast your expert eye over this and let me know if I'm on the right track please?
Any help greatly appreciated!
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