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ssaha
02-08-2010, 05:08 PM
I have been trying to use UserAvatar.py for navigation from link:
http://vizworkshop.com/articles/walkthrough_app

I did two following changes in UserAvatar file:

Change 1: In _init_ function, I used collideBox in place of collideCapsule.

Change 2: In updatePrePhysics, I changed headEuler following way:

headEuler = self.head.getEuler(viz.ABS_GLOBAL)
headEuler[0] = headEuler[0] + yawChange
headEuler[1] = headEuler[1]
headEuler[2] = headEuler[2]
self.head.setEuler(headEuler, viz.ABS_GLOBAL)


Problem: In code, there is no change of y-coordinate of self.feet. According to code, it should be
always zero (0). But when I run the code with above change, I get change in y-coordinate of self.feet. So in order to keep it zero, I add following code in updatePostPhysics:

temp_pos= self.feet.getPosition(viz.ABS_GLOBAL)
temp_pos[1]=0
self.feet.setPosition(temp_pos)


After doing this , y is zero . But movement is not smooth.


Could you give some solutions? For your convenience, updated UserAvatar.py is attached below.



import viz
import vizact
import vizmat
import viztask

class UserAvatar(viz.EventClass):
THROTTLE_SPEED = 4
HYPER_THROTTLE_SPEED = 30
TURN_SPEED = .1
def __init__(self):
viz.EventClass.__init__(self)
self.feet = viz.addGroup(pos=[0, 0, 0]) #position of user avatar

#physics init
self.physicShape = self.feet.collideBox([0.5,1,0.5],friction=.00000001, hardness=.0000001, bounce=0)
self.velMotor = self.feet.addVelocity(velocity=[0,0,0], maxForce=100, gravity=False))

#orientation of user avatar
self.head = viz.addGroup()
#view should link to this
self.avatar = viz.mergeLinkable(self.feet, self.head)
self.count =0;
self.mouseDx = 0
self.mouseDy = 0
self.callback(viz.MOUSE_MOVE_EVENT, self.onMouseMove)

vizact.onupdate(viz.PRIORITY_PHYSICS-1, self.updatePrePhysics)
vizact.onupdate(viz.PRIORITY_PHYSICS+1, self.updatePostPhysics)

def updatePrePhysics(self):
print "count " +str(self.count)
self.count =self.count+1
throttle = vizmat.Vector([0,0,0])
print "vizmat.Vector:Feet Pos: " + str(self.feet.getPosition(viz.ABS_GLOBAL))
## Steer Control
yawChange = self.mouseDx * self.TURN_SPEED
pitchChange = -self.mouseDy * self.TURN_SPEED
#discard old mouse movement and start collecting new mouse input
self.mouseDx = 0
self.mouseDy = 0
'''
headEuler = self.head.getEuler(viz.ABS_GLOBAL)
headEuler[0] = headEuler[0] + yawChange


headEuler[1] = headEuler[1]
headEuler[2] = headEuler[2]

self.head.setEuler(headEuler, viz.ABS_GLOBAL)
'''
## Translate Control
throttle.set([0,0,0])
#forward/back
if viz.key.isDown('w') or viz.mouse.getState() & viz.MOUSEBUTTON_LEFT:
throttle += [0,0,1]
if viz.key.isDown('s') or viz.mouse.getState() & viz.MOUSEBUTTON_RIGHT:
throttle += [0,0,-1]
#left/right
if viz.key.isDown('a'):
throttle += [-1,0,0]
if viz.key.isDown('d'):
throttle += [1,0,0]
throttle.normalize() #<--direction
print "throttle.normalize:Feet Pos: " + str(self.feet.getPosition(viz.ABS_GLOBAL))

print "throttle.length():Feet Pos: " + str(self.feet.getPosition(viz.ABS_GLOBAL))
if viz.key.isDown(' ') or viz.mouse.getState() & viz.MOUSEBUTTON_MIDDLE:
throttle *= self.HYPER_THROTTLE_SPEED
else:
throttle *= self.THROTTLE_SPEED
print "viz.key.isDown:Feet Pos: " + str(self.feet.getPosition(viz.ABS_GLOBAL))
if throttle.length(): #if throttle not zero
#move forward in direction of head
newVel = vizmat.Transform()
newVel.setTrans(throttle)
newVel.postEuler(self.head.getEuler(viz.ABS_GLOBAL ))
self.velMotor.setVelocity(newVel.getTrans())
else:
print "hey"
#self.velMotor.setVelocity([0, 0, 0])

print "throttle.length():Feet Pos: " + str(self.feet.getPosition(viz.ABS_GLOBAL))


def updatePostPhysics(self):

print "updatePostPhysics " + str(self.feet.getPosition(viz.ABS_GLOBAL))
self.feet.setEuler([0, 0, 0])

def onMouseMove(self, e):
#fuction called twice, once for movement on x axis, once for y axis
print "onMouseMove " + str(self.feet.getPosition(viz.ABS_GLOBAL))
self.mouseDx = self.mouseDx + e.dx
self.mouseDy = self.mouseDy + e.dy

def linkView(self, view):
return viz.link(self.avatar, view, srcFlag=viz.LINK_ABSOLUTE, dstFlag=viz.LINK_POS_RAW)

def setPosition(self, xyz):
self.feet.setPosition(xyz)
print "setPosition " + str(self.feet.getPosition(viz.ABS_GLOBAL))

def setEuler(self, euler):
self.head.setEuler(euler)

if __name__ == '__main__':
viz.go()
viz.move([0, 0, -2])
viz.phys.enable()
t = viz.add('tankmaze.wrl')
t.collideMesh(bounce=0, hardness=1, friction=0)
user = UserAvatar()
user.feet.setPosition([0, 0, 0])
user.linkView(viz.MainView)
ssaha
02-09-2010, 08:40 AM
I have been trying to use UserAvatar.py for navigation from link:
http://vizworkshop.com/articles/walkthrough_app

I did two following changes in UserAvatar file:

Change 1: In _init_ function, I used collideBox in place of collideCapsule.

Change 2: In updatePrePhysics, I changed headEuler following way:

headEuler = self.head.getEuler(viz.ABS_GLOBAL)
headEuler[0] = headEuler[0] + yawChange
headEuler[1] = headEuler[1]
headEuler[2] = headEuler[2]
self.head.setEuler(headEuler, viz.ABS_GLOBAL)


Problem: In code, there is no change of y-coordinate of self.feet. According to code, it should be
always zero (0). But when I run the code with above change, I get change in y-coordinate of self.feet. So in order to keep it zero, I add following code in updatePostPhysics:

temp_pos= self.feet.getPosition(viz.ABS_GLOBAL)
temp_pos[1]=0
self.feet.setPosition(temp_pos)


After doing this , y is zero . But movement is not smooth.


Could you give any solution? For your convenience, updated UserAvatar.py is attached below.


'''
Moves the view according to user input
'''

import viz
import vizact
import vizmat
import viztask

class UserAvatar(viz.EventClass):
THROTTLE_SPEED = 4
HYPER_THROTTLE_SPEED = 30
TURN_SPEED = .1
def __init__(self):
viz.EventClass.__init__(self)
self.feet = viz.addGroup(pos=[0, 0, 0]) #position of user avatar

#physics init
self.physicShape = self.feet.collideBox([0.5,1,0.5],friction=.00000001, hardness=.0000001, bounce=0)
self.velMotor = self.feet.addVelocity(velocity=[0,0,0], maxForce=100, gravity=False))
#orientation of user avatar
self.head = viz.addGroup()
#view should link to this
self.avatar = viz.mergeLinkable(self.feet, self.head)

self.mouseDx = 0
self.mouseDy = 0
self.callback(viz.MOUSE_MOVE_EVENT, self.onMouseMove)

vizact.onupdate(viz.PRIORITY_PHYSICS-1, self.updatePrePhysics)
vizact.onupdate(viz.PRIORITY_PHYSICS+1, self.updatePostPhysics)

def updatePrePhysics(self):
throttle = vizmat.Vector([0,0,0])
## Steer Control
yawChange = self.mouseDx * self.TURN_SPEED
pitchChange = -self.mouseDy * self.TURN_SPEED
#discard old mouse movement and start collecting new mouse input
self.mouseDx = 0
self.mouseDy = 0

headEuler = self.head.getEuler(viz.ABS_GLOBAL)
headEuler[0] = headEuler[0] + yawChange
headEuler[1] = headEuler[1]
headEuler[2] = headEuler[2]
self.head.setEuler(headEuler, viz.ABS_GLOBAL)

## Translate Control
throttle.set([0,0,0])
#forward/back
if viz.key.isDown('w') or viz.mouse.getState() & viz.MOUSEBUTTON_LEFT:
throttle += [0,0,1]
if viz.key.isDown('s') or viz.mouse.getState() & viz.MOUSEBUTTON_RIGHT:
throttle += [0,0,-1]
#left/right
if viz.key.isDown('a'):
throttle += [-1,0,0]
if viz.key.isDown('d'):
throttle += [1,0,0]
throttle.normalize() #<--direction
if viz.key.isDown(' ') or viz.mouse.getState() & viz.MOUSEBUTTON_MIDDLE:
throttle *= self.HYPER_THROTTLE_SPEED
else:
throttle *= self.THROTTLE_SPEED

if throttle.length(): #if throttle not zero
#move forward in direction of head
newVel = vizmat.Transform()
newVel.setTrans(throttle)
newVel.postEuler(self.head.getEuler(viz.ABS_GLOBAL ))
self.velMotor.setVelocity(newVel.getTrans())
else:
self.velMotor.setVelocity([0, 0, 0])


def updatePostPhysics(self):
self.feet.setEuler([0, 0, 0])

def onMouseMove(self, e):
#fuction called twice, once for movement on x axis, once for y axis
self.mouseDx = self.mouseDx + e.dx
self.mouseDy = self.mouseDy + e.dy

def linkView(self, view):
return viz.link(self.avatar, view, srcFlag=viz.LINK_ABSOLUTE, dstFlag=viz.LINK_POS_RAW)

def setPosition(self, xyz):
self.feet.setPosition(xyz)

def setEuler(self, euler):
self.head.setEuler(euler)

if __name__ == '__main__':
viz.go()
viz.move([0, 0, -2])
viz.phys.enable()
t = viz.add('tankmaze.wrl')
t.collideMesh(bounce=0, hardness=1, friction=0)
user = UserAvatar()
user.feet.setPosition([0, 0, 0])
user.linkView(viz.MainView)
Gladsomebeast
02-10-2010, 10:28 AM
Replied to here:
http://vizworkshop.com/articles/walkthrough_app#comment-3

Answer:
I could not reproduce the problem. I made your changes to UserAvatar.py and movement is smooth. Perhaps if you post your UserAvatar.py I can see your problem. The one you posted does not have your change to the "updatePostPhysics" method.

The problem could be because your moving the physics shape/box inside of another physics object, the tankmaze floor, with your updatePostPhysics method. This could be generating some strong "repelling" forces and make your movement jerky/weird. Hold the feet Y value at 1 or above to fix.

Also, the corners of collideBox cause some funky jerks when running into the hedra shape. Change back to smooth object like capsule or sphere to fix.
ssaha
03-24-2010, 01:21 PM
Thanks for your reply.

According to your instruction, I changed. But, still, movememnt is not smooth. Please check the attached code.