[x3d-public] passive vs. active mouse isOver event

Andreas Plesch andreasplesch at gmail.com
Mon Nov 7 19:52:22 PST 2016

On Nov 7, 2016 8:12 PM, "Joe D Williams" <joedwil at earthlink.net> wrote:
> How about when the touch is animated away from the pointer. Should isover
fo off, of stay on until the pointer is moved? What if another touch moves
over the first?

Good question:
Just restating to confirm:
If the pointer actively moves over the geometry but then stops moving while
the geometry is animated away, the question is if an isOver false event
should be generated.

The spec. indicates no but I (perhaps as many others) would expect yes.

An example application would be a task where a test subject needs to follow
a ball with the mouse, for example to measure eye-hand coordination delays.

> What ever the spec history, what about Octaga? we need to recognize BS as
the leading implementation and be sure to ask them. This should be a test.

Yes, that would be interesting.

> Also, maybe more like a collision sensor. That is how I used the pointer
when I expected that when an anchor moved under the pointer, then the link
was live. In real life it doesn't matter which has moved, if there is a
touch sensor, then it has to be evaluated each frame. That is what I
learned from flux and bs.

It will come down to discovering relevant use cases. If there are examples,
it would be great to see them.

> Also, part of accessibility.
> Maybe I have a good intention and wish to help the user by offering
choices by moving them under the pointer? Sure, you may need a click, but,
with a simple animation, shouldn't I be able to move the touch to get a


> OK, maybe this is hard to do in DOM, but DOM never had to deal with this,
in the sense of 3D.

It would not be difficult to do in a web browser. The DOM is unrelated.
Cobweb just follows the spec. which is very valuable unless most other x3d
browsers do not.

> ...It is a touchsensor and when touching, you what it to be live, not
delayed until i make a movement, or whatever, anyway maybe silly, but an
important little detail about how we represent the environment and our
interactions with it,

That was also my initial expectation. Just something to keep in mind,

> f----- Original Message ----- From: "Don Brutzman" <brutzman at nps.edu>
> To: "Andreas Plesch" <andreasplesch at gmail.com>; "X3D Graphics public
mailing list" <x3d-public at web3d.org>
> Sent: Monday, November 07, 2016 9:09 AM
> Subject: Re: [x3d-public] passive vs. active mouse isOver event
>> On 11/5/2016 2:46 PM, Andreas Plesch wrote:
>>> I noticed that cobweb does not generate an isOver TouchSensor event
when the pointing device is not moved actively but the sensed geometry
itself moves under the mouse pointer. At first this was surprising to me
but after reading
>>> this seems to be the expected behaviour since active mouse movement is
required to generate events.
>> ======================================================
>> The isOver field reflects the state of the pointing device with regard
to whether it is pointing towards the TouchSensor node's geometry or not.
When the pointing device changes state from a position such that its
bearing does not intersect any of the TouchSensor node's geometry to one in
which it does intersect geometry, an isOver TRUE event is generated. When
the pointing device moves from a position such that its bearing intersects
geometry to one in which it no longer intersects the geometry, or some
other geometry is obstructing the TouchSensor node's geometry, an isOver
FALSE event is generated. These events are generated only when the pointing
device has moved and changed `over' state. Events are not generated if the
geometry itself is animating and moving underneath the pointing device.
>> ======================================================
>>> Do other browser behave the same way ?
>> yes good question, glad people are checking...
>> I wondered if we should add a boolean field for this, but it seems clear
that user interaction is an intended prerequisite for TouchSensor activity
(i.e. "touching").   If an author wants something to occur when geometry
becomes visible, they can use VisibilitySensor instead.
>> 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 +1.831.656.2149
>> X3D graphics, virtual worlds, navy robotics
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