[Cesium3DTileStyleEngine] Missing support of access to values which are not in batch table, but present

[SunBlack]

It is currently not possible to access coordinates from a Cesium3DTileStyle.

An example would be:

tileset.style = new Cesium3DTileStyle({
	"color" : {
		"conditions" : [
			["(${x} < ${offset} || ${x} > ${offset} + ${maxHeight})", "rgb(255, 255, 255)"],
			[true, "rgb((${x} - ${offset})/${maxHeight}, 230, 230)"],
		]
	}
});

It would be also nice if you have access to BoundingBoxes and other properties of a tileset, so a support of following attributes would be nice:

• x/y/z
• bounding box of current tile
• bounding box of root tileset
• level in tree of current tile, starting from root tileset

[lilleyse]

Thanks for the suggestions, I will add them to the styling roadmap.

For point clouds, accessing the position is already available. The spec hasn't been updated yet, but here is a draft:

${POSITION} is an array of three values representing the xyz coordinates of the point before the RTC_CENTER and tile transform are applied. When the positions are quantized, ${POSITION} refers to the position after the QUANTIZED_VOLUME_SCALE is applied, but before QUANTIZED_VOLUME_OFFSET is applied.

There are also a few examples in the Sandcastle demo:
http://cesium-dev.s3-website-us-east-1.amazonaws.com/cesium/3d-tiles/Apps/Sandcastle/index.html?src=3D%20Tiles%20Point%20Cloud%20Styling.html&label=Showcases

[SunBlack]

Well thanks for the hint with ${POSITION}. But without access to any offset it is currently not really usefull with point clouds (or I need to adjust each tile to have same RTC-Center ;-) ).

[lilleyse]

Yeah pretty much, we've wanted to support bounding volume information in the styling for a while.

[pjcozzi]

we've wanted to support bounding volume information in the styling

CC CesiumGS/3d-tiles#127