NodeMaterial: Update perturbNormal2Arb back/double-sided math.

[donmccurdy]

Update to match changes from #13916, per #14237 (comment).

I'm not sure this fixes bumpmaps in NodeMaterial or how to reproduce that difference, but the DamagedHelmet example looks correct.

/cc @WestLangley

[WestLangley]

Add workaround for Adreno 3XX dFd*( vec3 ) bug?

[WestLangley]

/ping @sunag

[sunag]

Currently bumpMap is converted to normalMap in NodeMaterial but in PR I will going to release I am following exactly the same as in the core.

Just remembering that an extra attention is needed to rename function inputs:
vec2 scale to vec2 normalScale

It is parsed in runtime and can be used with others nodes in functionCallNode.inputs.scale = ....
For example:

three.js/examples/webgl_materials_nodes.html

Lines 1108 to 1118 in a41ca87

	var satrgb = new THREE.FunctionNode( [
	"vec3 satrgb(vec3 rgb, float adjustment) {",
	//" const vec3 W = vec3(0.2125, 0.7154, 0.0721);", // LUMA
	" vec3 intensity = vec3(dot(rgb, LUMA));",
	" return mix(intensity, rgb, adjustment);",
	"}"
	].join( "\n" ) );
	var saturation = new THREE.FunctionCallNode( satrgb );
	saturation.inputs.rgb = tex;
	saturation.inputs.adjustment = sat;

[sunag]

more directly fix bumpMap too since bumpMap uses perturbNormal2Arb

[sunag]

#14333

I think that these fixes are already here?
https://github.com/sunag/three.js/blob/085bd767e4e2f1701ab008e7dbe6149512a2a4cc/examples/js/nodes/libs/common.js#L11-L41

[donmccurdy]

Looks like @sunag got it, thanks!