From: Hannu Lesonen (hlesonen++at++levi.urova.fi)
Date: 01/17/2001 01:43:12
Dear Gurus,
This question is not directly related to Performer, but to USB devices. I
am
sending this in hopes that some of You might have run into similar
problems
with different software systems.
We have been making a virtual reality simulation using HMDs, InterSense
InterTrax2 -motiontrackers (USB-version), and Logitech's cordless wheel
mice
on USB. The simulation runs on Windows 2000 -platform with 1 GHz Pentium
processor and Nvidia GeForce2 on AGP and with 64 Mb of TRAM. The
simulation
is done with WorldUp 5.0 with patch 2, and includes WorlUp Plug-In Kit
dlls
coded by us, one of which uses DirectX -calls to aqcuire the mouse from
Windows (this is done to get rid of the WorldUp restrictions of mouse
stopping on the edge of the screen).
The problem is that we can't get the trackers and mice to cooperate
together
at the same time. We have the mice and trackers connected to the USB-HUB
at
the end of a series of active USB cables (all in all the cabling consists
of
one passive 5 m USB, four active 5 m USBs plus a two port USB HUB per
computer) when we boot the computers. The solution to get the simulation
up
with this cabling requires that before we start the simulation we unplug
the
mice, start the simulation, and when the simulation is running we plug the
mice back in. If we try to start the simulation with the mice also plugged
into the HUB, the simulation stops in a couple of seconds trying to read a
NULL address. When everything goes well, the simulation start takes about
half a minute because of lots of models and some heavy precalculations, so
it seems that the problem takes place before our own code starts to
initialize itself.
Also, after running the simulation once, we can't use the above solution
without rebooting the machines. The simulation just won't take the
trackers
into use anymore. Weird, uh?
We have also used the simulation with mouse on a PS/2 port, and that has
always worked fine (that is, we don't have to unplug anything nor reboot
the
machines), but because of the long distances from the computers to the
area
where the users are situated, we thought using USB cabling would be easier
because of the possibility of including two devices on one cabling.
So, has anyone out there ever run into this kind of problem with USB
devices, or specifically with USB InterTrax2 -trackers? One solution of
course would be to use the PS/2 cabling, but that requires a lot of
physical
work to install new cablings into the simulation building, so we have to
check the other possibilities first.
Any help would be greatly appreciated.
Thank You,
Hannu Lesonen
Valkeus Interactive Inc.
Finland
This archive was generated by hypermail 2b29 : Wed Jan 17 2001 - 02:43:31 PST