NodeMaterial - fix name conflict + label + gets and sets

[sunag]

Issue

#15666

New examples

label
https://rawgit.com/sunag/three.js/dev-fix-nameconflict/examples/webgl_materials_nodes.html?e=label

Description

• fix Conflicting names for varying and temp var issue NodeMaterial: Conflicting names for varying and temp var. #15666
• new setLabel and getLabel in TempNode
• new internal var names:
  • nodeU0 = node uniform id
  • nodeV0 = node varying id
  • nodeT0 = node temp id
• isShared, isUnique, isReadonly renamed to getShared, getUnique, getReadonly

Usages

label

var colorInput = new THREE.ColorNode( 0xFFFFFF ).setLabel( "colorInput" );
var specularInput = new THREE.FloatNode( .5 ).setLabel( "specularInput" );

var colorMix = new THREE.OperatorNode(
	colorInput,
	new THREE.ColorNode( 0x6495ED ).setReadonly( true ),
	THREE.OperatorNode.MUL
).setLabel("colorMix");

mtl.color = colorMix;
mtl.specular = specularInput;

optimization alerts
https://github.com/sunag/three.js/blob/40651f3fa6e6b12a2ae145cf3de14efde04065d3/examples/webgl_materials_nodes.html#L2543

https://github.com/sunag/three.js/blob/40651f3fa6e6b12a2ae145cf3de14efde04065d3/examples/webgl_materials_nodes.html#L2560

readonly

material.color = new THREE.ColorNode( 0xFFFFFF ).setReadonly( true );

[mrdoob]

Thanks!

[donmccurdy]

Works here, thanks! :)