[x3d-public] PointProperties revisited

[Michalis Kamburelis]

I second this. I would be best if we can simply render points *in the same,
exact way, using the same texture/color/lighting equations* as all other
geometric nodes.

The existing prose for rendering already says what to do with textures,
colors, lighting etc. Let's let the same equations be just used for points
(and lines, BTW). Of course the non-unlit lighting models are only
available if explicit normals are provided. But when normals are provided,
points and lines can just utilize the same rendering logic as other nodes.

This would also be consistent with glTF.

Regards,
Michalis

niedz., 23 sie 2020 o 06:43 Andreas Plesch <andreasplesch at gmail.com>
napisał(a):

>
> https://www.web3d.org/specifications/X3Dv4Draft/ISO-IEC19775-1v4-WD2/Part01/components/shape.html#PointProperties
>
> has the current draft.
>
> What is the motivation for having a colorMode field ? Should coloring
> not be handled the same way as it is for other geometries, eg. use
> color if no texture, use texture if no color, and blend if both are
> provided ? Other geometries do not require a colorMode field after
> all.
>
> Even if there is an additional benefit of having the colorMode field, I
> think "
> TEXTURE_AND_POINT_COLOR" should multiply rather than add:
>
> "TEXTURE_AND_POINT_COLOR shall display the RGBA channels of a texture
> added to the RGB channels of the color defined in X3DMaterialNode or
> X3DColorNode node, and the A channel of the texture if any."
>
> Adding introduces the problem of how to deal with oversaturated
> components and contradicts how combining colors is defined for other
> geometries.
>
> Also, only RGBA textures are mentioned. Should one component (alpha),
> 2 component (greyscale plus alpha) and 3 component (RGB) textures also
> be allowed or well defined ?
>
>
> https://www.web3d.org/x3d/content/X3dTooltips.html#PointProperties.containerField
>
> has a copy and paste typo. It still refers to "lineProperties"
>
> -Andreas
> --
> Andreas Plesch
> Waltham, MA 02453
>
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