[x3d-public] Units for BVH vs HAnimMotion.values

[John Carlson]

Joe, in a text editor, to move the decimal point for 150+ numbers is
inhumane.  If you’ve got a macro for it, please share.

And you would have to do this each time you generate a file.

Be my guest.

On Sat, Oct 14, 2023 at 1:45 PM Joe D Williams <joedwil at earthlink.net>
wrote:

> Joe > We are not using it that way because we will always interpolate.
>
>
>
> "always" meaning realtime may allow interpolating between key times, even
> if keyframes are provided at standard video/film frame rates. It is typical
> that through good use of interpolation, key times and keyValues can and
> should be much reduced.
>
>
>
> Another issue is what to do when the dimensions for hanim model like
> skeleton or skin are given in cm and HAnim wants m. One solution is to
> simply scale by 0.01 in the user code. As you will probably see when you
> try to animate the thing lthat the rescale solution was too simple.
>
>
>
> But wait, I didn't forehead slaps when I said just move the decimal point
> instead of multiplying by 0.01 (to get m from cm). Recall that in
> authortime, which is when you want to make the conversion, we have a text
> file. So, for any case, moving the decimal point using a text editor in
> authortime is more accurate in terms of representing the author's intent,
> than multiply by 0.01 in runtime.
>
>
>
>
>
>
>
> -----Original Message-----
> From: John Carlson <yottzumm at gmail.com>
> Sent: Oct 13, 2023 6:17 PM
> To: Joe D Williams <joedwil at earthlink.net>
> Cc: GPU Group <gpugroup at gmail.com>, X3D Graphics public mailing list <
> x3d-public at web3d.org>
> Subject: Re: [x3d-public] Units for BVH vs HAnimMotion.values
>
>
> > Agreed that BVH/HAnimMotion should be converted to Interpolators, hence
> my plea for shared keys between Interpolators.
>
> Don't concern yourself about the repetition. It is what it is. We just
> have to deal with it.The bch will probably include a key for each video
> frame since one objective is to not do any interpolation. We are not using
> it that way because we will always interpolate.
> The next step to make it usable is to process to remove extra keys and
> keyvalues. If small frame interval, then probably lots of extra frames when
> we can interpolate.
>
> > Should I look into a single MetadataFloat for all Interpolators keys?
>
> No because the right way, without a script is to justeliminate unneeded
> keys andkeyvalues.
> Maybe a different project task than getting Grampsrunning.
>
> > Programming a script that won't work in view3dscene?
>
> Not a real help now.
>
> > Mot Using a PROTO that may not work across all Interpolator node types?
> Doing a PROTO per Interpolator type and animation sequence?  How many
> ProtoInstances do you want to see in your animation code?  Abandoning
> HAnimMotion as unworkable seems reasonable, except for bloat.
>
> Just don't worry about that bloat for now.
>
> Joe
>
> On Fri, Oct 13, 2023 at 7:07 PM Joe D Williams <joedwil at earthlink.net>
> wrote:
>
>> > Apparently BVH uses degrees for rotations.
>>
>>
>>
>> It is not specified. There is no spec. Degrees do not appear in any x3d
>> user code, or any where else except these too simple to use directly random
>> examples in random bvh archives, or defult spitout of some glorified
>> animation tool. char. Literally any animation tool worth having does not do
>> them in terms of degrees, junk coding. If tool cannot export quaternions or
>> axis-angle it is not worth using. And just because the helpdesk doesn't
>> know about it doesn't mean they don't have it.
>>
>>
>>
>> The conversion from typical bvh to axis-angle is in Part 2.
>>
>> Just do the conversion and don't worry about using angles anymore. There
>> is no standard way to interpolate angles, and for good reason.
>>
>>
>>
>> A bvh file is NOT x3d user code, it is just a partially documented
>> importation that may be adapted for use with x3d HAnim. This is true no
>> matter if it comes from some instructor-student archive somewhere on the
>> web, or hot off the press to represent some current character animation
>> tool generated keyframes. Even if pretty-printed with x3d it is not x3d.
>>
>>
>>
>> Just convert the stuff and apply to skeleton. Don't deal with the angles
>> bs except to convert it to x3d interpolators. It is just an import format,
>> not standard, and not x3d.
>>
>>
>>
>> Just convert for most fun,
>>
>> Joe
>>
>>
>>
>>
>>
>>
>>
>>
>>
>> -----Original Message-----
>> From: GPU Group <gpugroup at gmail.com>
>> Sent: Oct 13, 2023 12:48 PM
>> To: John Carlson <yottzumm at gmail.com>
>> Cc: X3D Graphics public mailing list <x3d-public at web3d.org>
>> Subject: Re: [x3d-public] Units for BVH vs HAnimMotion.values
>>
>>
>> I have the same question and posted it on h-anim. Might help to have some
>> options and analysis of the options.
>>
> 1. Units statement
>> Analysis: that would apply to all rotations in the file, including other
>> scenery Transform rotations which is awkward for most workflows
>> 2. Motion.values in radians by default
>> Analysis: will break some scene example data such as HAnim Annex D
>> Motion.values which is in degrees
>> - would need to update Annex D
>> 3. Motion.values in radians by default, and browsers can support degrees
>> with a field
>> Motion {
>> SFString [] angleUnits 'RADIANS' ['RADIANS', 'DEGREES']
>> //or
>> SFBool [] angleUnitsDegrees FALSE
>> }
>> Analysis: would still break the Annex D example which doesn't show any
>> Motion field for angle units, and would need to update the specification
>> for Motion to include an additional field.
>> 4. export in degrees, and put an export option on the export option panel
>> for Motion data in [degrees, radians] so browsers will still work either
>> way until a more permanent solution such as 2 or 3.
>> Q. how many web3d browsers have implemented HAnimMotion and angle units
>> did you use for Motion.values ?
>> -Doug
>>
>> On Fri, Oct 13, 2023 at 12:44 PM John Carlson <yottzumm at gmail.com> wrote:
>>
>>> Apparently BVH uses degrees for rotations.  Units for HAnimMotion should
>>> use radians unless otherwise specified in a UNIT statement, AFAIK.
>>>
>>> Comments?
>>>
>>> Thanks!
>>>
>>> John
>>> _______________________________________________
>>> x3d-public mailing list
>>> x3d-public at web3d.org
>>> http://web3d.org/mailman/listinfo/x3d-public_web3d.org
>>
>>
>>
>
>
>
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://web3d.org/pipermail/x3d-public_web3d.org/attachments/20231014/fb6466a3/attachment.html>