WorldViz User Forum  

Go Back   WorldViz User Forum > Precision Position Tracker (PPT)

Reply
 
Thread Tools Rating: Thread Rating: 2 votes, 5.00 average. Display Modes
  #1  
Old 04-19-2010, 03:50 PM
v-clizzin v-clizzin is offline
Member
 
Join Date: Sep 2006
Posts: 15
Moving main viewpoint when linked to PPT

I'm currently debugging an old falling-into-a-pit demo; the problem is that the viewpoint does not actually move downwards when the user 'falls' into the pit.

I initially set up PPT tracking like so:

Code:
vrpn = viz.add('vrpn7.dle')
ppt = vrpn.addTracker('PPT0@' + PPT_HOSTNAME)
filter = viz.add("filter.dle")
ppt = filter.average(ppt, samples = 5)

view = viz.MainView
link = viz.link(ppt, view)
link.reset(viz.RESET_X|viz.RESET_Y|viz.RESET_Z)
viz.eyeheight(0.0)
The code for moving the viewpoint downward is:

Code:
fallV -= 9.8 * viz.elapsed() # fallV is initialised at 0 when the fall begins
viz.translate(viz.HEAD_POS,0,fallV*viz.elapsed(),0)
However, the viewpoint does not move downward. I do know from print statements that fallV is being updated correctly. I've tried using link.setPos(ppt.getPosition()[0], ppt.getPosition()[1] + fallV, ppt.getPosition()[2]), but that simply makes the view jump to floor level height and does not move further down thereafter. Perhaps I don't fully understand the interaction between PPT, the main viewpoint, and the link between the two.

This may also have something to do with the fact that this demo was written during our serial PPT days, and the update to make it work with VRPN may not have ironed out all the kinks.

Any ideas? Thank you!
Reply With Quote
  #2  
Old 04-20-2010, 05:09 PM
Jeff Jeff is offline
WorldViz Team Member
 
Join Date: Aug 2008
Posts: 2,471
When the viewpoint is linked to the tracker trying to set it's position will not have any effect. In your timer function that moves the view down you could do something like:
Code:
link.reset(viz.RESET_OPERATORS)
link.postTrans([0,fallV,0])
then when you want to move the view back up you would use:
Code:
link.reset(viz.RESET_OPERATORS)
Reply With Quote
Reply

Thread Tools
Display Modes Rate This Thread
Rate This Thread:

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
How to track the actual viewpoint Jerry Vizard 3 05-25-2016 10:44 AM
Avatar w/ hat cannot look at viewpoint TrashcanPatrol Vizard 5 08-19-2008 09:26 AM
3d viewpoint movement spacefarer Vizard 9 07-25-2006 04:37 PM
moving viewpoint vs. translating Head_pos bailenson Vizard 5 02-01-2005 02:51 PM
VRML Viewpoint error bstankie Vizard 1 03-11-2003 03:10 PM


All times are GMT -7. The time now is 10:40 AM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2024, vBulletin Solutions, Inc.
Copyright 2002-2023 WorldViz LLC