[X3D-Public] my musings on O3D and JavaScript on the web

miriam miriam at werple.net.au
Fri May 1 17:50:38 PDT 2009

Hi Joshua,

For some years I worked in a conventional animation studio drawing 
cartoons for TV on paper which was transferred to cel and photographed. 
I find conventional page-flipping animation very easy to understand. But 
I find interpolators difficult to grapple with. I have never once 
managed to make a usable VRML animation without having a manual and 
examples in front of me. And I'm not lacking in computer language skills 
either, having taught myself more than a dozen computer languages.

There have been fairly complex attempts to make PROTOs that animate in a 
way similar to what you mention, but that really just points up the 
inadequacy of the standard system: that to do straightforward animation 
we need to add a complex set of PROTOs.

We have the Sphere node in VRML. It makes world authoring a heck of a 
lot easier than having to calculate a spherical mesh each time. VRML/X3D 
should apply the same principles to animation. It takes the smartest of 
us a lot of sweat and tears to animate simple stuff. I've long felt this 
is a major obstacle to acceptance of VRML.

Show a kid how to build a VRML world and their excitement lights them 
up. Show them how to animate in VRML and the shut-down and loss of 
interest is instant and obvious. This has to say something.

It amazes me that Thyme's animation extensions were never incorporated 
into VRML/X3D. (Look up Seamless3D on Wikipedia.) These additions would 
have attracted far more interest to VRML/X3D than the interpolator way 
of doing things. Seamless3D is a brilliant VRML/X3D modeler and 
animator. To get around many of the limitations in VRML/X3D he created 
an internal language based on VRML that is far easier to use. Given the 
current interest in VR shown by Google, I'd think people would be 
interested in adopting his superb techniques. He's already done all the 
work. And it is really simply a modification to VRML. You have the next 
version of VRML waiting for you right there if you want it. (Forget XML 
encoding. After all these years I still I don't know one person who 
writes worlds in the XML encoding.)

Best wishes,

	- Miriam

Joshua Smith wrote:
> I think that depends on how you define "people".
> Interpolators come from the world of "Key Frame Animation" which goes 
> all the way back to flipping pages with charcoal drawings on them.  So 
> the concept is immediately familiar to anyone in the "Animation" side of 
> the world (people who use tools like After Effects, Shake, Flash, etc.).
> But as you rightly point out, interpolators are completely useless when 
> defining "Simulations".
> But you don't have to use them for that, do you?  I'm not VRML/X3d 
> expert, but can't you set up routes and fire whatever numbers you want 
> into the scene graph's transform matrices?
> Any good 3D scene graph API really should define both, although 
> technically, you can create interpolators from routes, but you cannot 
> create routes from interpolators (except in a weird, bounded fashion).
> -Joshua
> On Apr 28, 2009, at 6:28 AM, miriam wrote:
>> But one thing I *must* correct is Len's statement that "Interpolators 
>> for example, are a pretty good authoring hedge because most people get 
>> the idea of clock ticks and points on a line."
>> No way! Len, I think you are the greatest, but boy, are you wrong 
>> here! Interpolators are great for the browser programmers but they are 
>> actually antithetical to how most people think and it takes quite a 
>> bit of mind-stretching to get used to them. Ask someone how they want 
>> to move something and they'll generally say something like "that 
>> direction at that speed", whereas interpolators require start point, 
>> start time, end point, end time, and if the movement is not constant 
>> then one or more inbetween point and inbetween time too.

If you don't have any failures then you're not trying hard enough.
  - Dr. Charles Elachi, director of NASA's Jet Propulsion Laboratory
Website: http://miriam-english.org
Blog: http://miriam_e.livejournal.com

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