[x3d-public] FloatSequencer ? step functions and optimization, avoiding node bloat

[Don Brutzman]

On 10/10/2017 7:36 AM, Andreas Plesch wrote:
> On Oct 9, 2017 11:02 PM, "Andreas Plesch" <andreasplesch at gmail.com 
> <mailto:andreasplesch at gmail.com>> wrote:
> 
>     Good points but consider:
> 
>     Interpolators with step functions act almost like sequencers but do not have
>     the 'next' and 'previous' fields. These fields could be added, however.
>     'next' would proceed to next keyValue interval, either to the lower limit or
>     to the equivalent interpolated value within that interval. With these
>     fields, I agree, there would be no need for more sequencers.

true.  though the notion of /next/ and /previous/ wouldn't seem to be workable 
for interpolators since each range interval can be nonlinear or even 
instantaneous/discontinuous.

so this point about gaining /next/ and /previous/ functionality is actually a 
good justification in support of defining sequencer nodes for floating-point values.

> Another, perhaps less invasive approach would be to allow integers as input to 
> interpolator key fields. Then IntegerSequencer could be used to drive any 
> interpolator. Although keys are often in the 0 to 1 range, they can have any value.

as above, I don't think this can work for interpolators.

however we might have an inputOutput SFInt32 /index/ field for sequencers that 
would allow such selection and reporting of which range-interval is active. 
presumably setting index to value i would be equivalent to providing 
set_fraction value of key[i].

remaining task: ensuring the algorithm works in all cases, similar to current 
discussion on interpolator prose/equations.

[...]

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 http://faculty.nps.edu/brutzman