[x3d-public] MatrixTextureTransform node

Brutzman, Donald (Don) (CIV) brutzman at nps.edu
Thu Oct 24 08:05:43 PDT 2019


Thanks Andreas for bringing this up and help us think it through fully.

Wasn't able to find documentation at regular site.  An example or two would be interesting as well.

	https://doc.x3dom.org/
	https://doc.x3dom.org/author/nodes.html

Would MatrixTextureTransform functionality be similar to

	X3Dv4 Public Working Draft Specification
	18.4.10 TextureTransform
	http://www.web3d.org/specifications/X3Dv4Draft/ISO-IEC19775-1v4-WD1/Part01/components/texturing.html#TextureTransform

Also wondering if any variants of MatrixTextureTransform node are appropriate for 3D textures?  Presumably MultiTextureTransform is already sufficient.

	18.4.5 MultiTextureTransform
	http://www.web3d.org/specifications/X3Dv4Draft/ISO-IEC19775-1v4-WD1/Part01/components/texturing.html#MultiTextureTransform

presumably MatrixTextureTransform would inherit from badge interface

	18.3.4 X3DTextureTransformNode
	http://www.web3d.org/specifications/X3Dv4Draft/ISO-IEC19775-1v4-WD1/Part01/components/texturing.html#X3DTextureTransformNode

In general X3D specification development has avoided transformation matrices, only offering occasional access.  So a crisp use case would help, and also a rationale if we think that some animation or modification or sharing of assets within glTF models might occur.  Sometimes building an X3D prototype can help illustrate potential use and offer an example implementation as well.

If it looks like a candidate addition, then let's go ahead and add it to the Mantis issues list so that final prose/examples/implementation can be reviewed and documented 1Q2020 as we finalize X3Dv4.0 specification.  Looking forward to learning more.


On 10/21/2019 12:01 PM, Andreas Plesch wrote:
> x3dom introduced a MatrixTextureTransform node in the Texturing
> component, mostly to support glTF to x3d translation since gltf allows
> for such a texture coordinate transform matrix. It accepts a 2x2
> matrix which is the equivalent of the transformation matrix resulting
> from the scale and rotation of a regular TextureTransform node.
> 
> Such a node is more convenient than decomposing a provided matrix to
> use in a regular TransformMatrix node, only to then recalculate the
> matrix from the components when the actual texture coordinates are
> computed.
> 
> glTF support will make this node very desirable but I am not sure if
> other browser have something similar already.
> 
> -Andreas


all the best, Don
-- 
Don Brutzman  Naval Postgraduate School, Code USW/Br       brutzman at nps.edu
Watkins 270,  MOVES Institute, Monterey CA 93943-5000 USA   +1.831.656.2149
X3D graphics, virtual worlds, navy robotics http://faculty.nps.edu/brutzman


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