[X3D-Public] Accelerometer environment sensor

[Don Brutzman]

Keith Victor wrote:
> Hey Don:
>  
> I agree that an orientation_changed output field would be helpfull in 
> addition to the raw acceleration data.  For true 3D orientation, you 
> would also need compass input along with the accelerometer.  Or, is this 
> the 2D orienation, as I had described.  We need to clearly define this.

agreed.  another limitation is that you don't have a "fix" capability
to know where "zero" or "north" or "origin default orientation" might be.
Hence thus suggestion to define default orientation based on when
enabled field becomes true.

> In an ideal world, you can integrate acceleration to get relative 
> velocity.  And, once again to get relative position.  But, Im afraid 
> thats not going to work with these simple devices.  The acceleration of 
> gravity is so much stronger than anything else going on, that the only 
> thing it is good for is detecting the orientation of the device ( which 
> way is down ), and any extreme shaking.  You're not going to get any 
> good velocity data out of an iPhone ;(

that is a good question that is worth further checking - who can do that?

> What is the "IsActive" output field do?  Does that tell you if the 
> device supports this feature.  If its enabled, and working, its going to 
> be active. Perhaps SFBool isSupported   is a better name.

isActive is required as part of the X3DSensor abstract interface.
so applying your definition in this context sounds appropriate.

all the best, Don
-- 
Don Brutzman  Naval Postgraduate School, Code USW/Br           brutzman at nps.edu
Watkins 270   MOVES Institute, Monterey CA 93943-5000 USA  work +1.831.656.2149
X3D, virtual worlds, underwater robots, XMSF  http://web.nps.navy.mil/~brutzman