[X3D-Ecosystem] Soft body physics baking in Blender X3D export

[John Carlson]

Don,

It's pretty much water under the bridge at this point.  I am:

1.  Exporting with strings or ElementTree
2.  Reading the python scenegraph, not exporting
3.  Moved on to my own versions of X3DPSAIL, namely x3dv.py

While I may be able to provide support in the future, I cannot predict such
things.

I suggest you work with Aaron to get x3d.py exports working as expected, as
he probably has a lot more experience than I currently.

Thanks,

John

On Sat, Dec 6, 2025 at 1:07 PM Don Brutzman <don.brutzman at gmail.com> wrote:

> John, thanks for reporting that you are having problems with X3DPSAIL.
> However there is insufficient information that might enable investigation
> or duplication of each difficulty.
>
> Please post an issue for goal X3D and x3d.py X3DPSAIL source  (small
> fragments preferred if possible) at the following site.  If a prior issue
> pertains, that can help too.
>
>    - SourceForge x3d Tickets
>    - https://sourceforge.net/p/x3d/tickets
>
> all the best, Don
> --
> X3D Graphics, Maritime Robotics, Distributed Simulation
> Relative Motion Consulting  https://RelativeMotion.info
>
>
> On Thu, Dec 4, 2025 at 3:56 PM John Carlson <yottzumm at gmail.com> wrote:
>
>> Okay, Don!
>>
>> I noticed 3 things about most of the python:
>>
>> * missing HAnim component
>> * TimeSensor in wrong place
>> * missing joints field
>>
>> I hand edited these into place in the exported X3D.
>>
>> I agree that adding a creaseAngle should be easy.  I’ll probably add
>> crease angle to the python by hand.
>>
>> X3DPSAIL is another question, because I’d probably have to hand edit
>> exports due to DEF/USE.  Already TimeSensor is misplaced in my examples
>> (not the official blender exporter).
>>
>> Apparently,  creating facial features and positioning hair is much more
>> difficult, and UV textures need to be looked at more.  Also clothing.
>> There’s much to be desired.  However, coveroids matching the skin, like
>> blouse and pants have worked.
>>
>> Joe asked for HAnimSegments, but I’m not sure how to get those in/out of
>> Blender yet.  If someone has python that creates HAnimSegments properly,
>> great!
>>
>> This is only the beginning!
>>
>> John
>>
>> On Thu, Dec 4, 2025 at 12:44 PM Don Brutzman <don.brutzman at gmail.com>
>> wrote:
>>
>>> Thanks for an impressive set of examples John!  You are certainly
>>> demonstrating the "art of the possible" here.  Also confirming that
>>> "baking" such animations in advance can be a useful technique for real-time
>>> playback.
>>>
>>> Modeling suggestion: the given creaseAngle value helps show individual
>>> polygons... am expecting that with some adjustment, the cloth mesh will
>>> look completely smooth.
>>>
>>>    - X3D Tooltips, IndexedFaceSet, creaseAngle
>>>    -
>>>    https://www.web3d.org/x3d/tooltips/X3dTooltips.html#IndexedFaceSet.creaseAngle
>>>
>>> Wondering if you might want to adapt one of these programs to instead
>>> use x3d.py X3DPSAIL for source code?  Am hoping it would be easier to
>>> ensure that the .x3d you produce is always valid.  If so, and if there are
>>> any gaps in x3d.py library, then please post an issue and I can work on
>>> diagnosing or updating the library.
>>>
>>> all the best, Don
>>> --
>>> X3D Graphics, Maritime Robotics, Distributed Simulation
>>> Relative Motion Consulting  https://RelativeMotion.info
>>>
>>>
>>> On Wed, Dec 3, 2025 at 10:51 PM John Carlson via X3D-Ecosystem <
>>> x3d-ecosystem at web3d.org> wrote:
>>>
>>>> Here are the good results (well, perhaps) from baking soft-body physics
>>>> in a Blender script that exports X3D (without soft-body) as previously
>>>> mentioned.
>>>>
>>>> I have most of the python scripts (except for the one's I overwrote,
>>>> oops!) and the result .x3d.
>>>>
>>>> If you run the python script inside Blender, an output file should be
>>>> placed in your home folder, you'll have to check there.
>>>>
>>>> Once the baking and export is done, Blender will be available to view
>>>> the animation.  The question is, if you don't do the baking, will the
>>>> animation still work in Blender?  I don't really know at this point.  It
>>>> may be worth modifying the script to not do the baking, and see what
>>>> happens?
>>>>
>>>> I don't have problems doing soft-body physics in Blender, so I think
>>>> they would work one way or the other.  I did have a soft-body example that
>>>> didn't use cloth, and I recall that working, but i can't swear by it.
>>>>
>>>>
>>>> John
>>>>
>>>>  pseudosoftbodyphysics.zip
>>>> <https://drive.google.com/open?id=1IaZbrWZD6N3GxSf_u15vVPiHLljc3x2B>
>>>>
>>>> On Tue, Dec 2, 2025 at 2:13 AM John Carlson <yottzumm at gmail.com> wrote:
>>>>
>>>>> I’ve been working with soft body physics baking in Blender X3D export
>>>>> to CoordinateInterpolator and I’m wondering if anyone is interested in this
>>>>> feature in the main exporter.  Just be warned, it will be an optional
>>>>> feature, to be replaced by a soft body solution in the standard.  Also be
>>>>> aware, I’ve personally seen it take over 50 minutes for 250 frames to
>>>>> export, with just one soft body. But I remember the days when it took 2
>>>>> hours for 1 frame, in 1986.  The interpolator performs adequately, but with
>>>>> low resolution sampling.
>>>>>
>>>>> So far, it’s not a great solution, a soft body may go right through a
>>>>> solid object.  I don’t know if that’s Blender, AI or a sampling issue
>>>>> currently.
>>>>>
>>>>> I am thinking of a custom property or other identifier for soft bodies
>>>>> may be indicated.
>>>>>
>>>>> Does anyone know if Transforms can be used to adjust
>>>>> CoordinateInterpolators, potentially by adjusting Coordinate.point via
>>>>> matrix multiplication?
>>>>>
>>>>> John
>>>>>
>>>> --
>>>>
>>> X3D-Ecosystem mailing list
>>>> X3D-Ecosystem at web3d.org
>>>> http://web3d.org/mailman/listinfo/x3d-ecosystem_web3d.org
>>>>
>>>
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