[x3d-public] gltf inspired binary storage

[Michalis Kamburelis]

@Andreas -- Not yet. CGE/view3dscene doesn't yet read morph targets.
But we will -- either into CoordinateInterpolator, or into specialized
nodes to express them, so that we don't lose any information from glTF
(otherwise "compiling" them into CoordinateInterpolator would have
them premultiplied by weights; the most important disadvantage of it
is that we would not be able to later operate on morph targets
programmatically, and the latter is a useful feature).

@Joe -- Morph targets in glTF specify displacement. See
https://www.khronos.org/registry/glTF/specs/2.0/glTF-2.0.html#morph-targets
,

"""
Morph targets are specified via the targets property defined in the
Mesh primitives. Each target in the targets array is a plain JSON
object mapping a primitive attribute to an accessor containing morph
target displacement data (deltas).
"""

(see further prose around there for more info.)

Regards,
Michalis

czw., 20 sty 2022 o 16:36 Andreas Plesch <andreasplesch at gmail.com> napisał(a):
>
> Let me just note that x3dom currently does not support morph targets or sparse accessors in glTF. Does castle engine translate morph targets to CoordinateInterpolators ?
>
> Regards, Andreas
>
> On Thu, Jan 20, 2022 at 6:47 AM Michalis Kamburelis <michalis.kambi at gmail.com> wrote:
>>
>> Hi Joe,
>>
>> > Can we also compare this with Hanim Displacer operation (target displacements of mesh and weights driven by 0 to 1 scale input) ?
>>
>> From what I understand,
>>
>> - H-Anim Displacer means that you animate a (subset) of coordinates of the mesh.
>> - Which is equivalent in Blender to using a "hook" attached to a
>> vertex group. Useful e.g. to animate a jaw, or eye area, to make
>> facial expressions -- when you want to morph a mesh, but usually only
>> a small subset of the mesh changes by a particular animation.
>> - From what I understand this is equivalent to glTF morph target
>> animation with "Sparse Accessors",
>> https://www.khronos.org/registry/glTF/specs/2.0/glTF-2.0.html#sparse-accessors
>> .
>>
>> >
>> > Can the glTF change number of points in a shape during the course of an animation?
>>
>> No. Morph targets just change the coordinates' positions. Number of
>> points, as well as their topology (how they connect to polygons)
>> always stays the same.
>>
>> Regards,
>> Michalis
>
>
>
> --
> Andreas Plesch
> Waltham, MA 02453