AttributeNode: .nodeType is now optional

[sunag]

Description

Usage:

// auto node type
material.colorNode = attribute( 'color' );

// declared node type
material.colorNode = attribute( 'color', 'vec3' );

This contribution is funded by Google via Igalia

[LeviPesin]

I think it is better to just make getConstNodeType return undefined if input is undefined.

[sunag]

What kind of use did you imagine when you implemented this function? For this case, I see only 3 type of usage:

// name only
attribute( 'color' );

// typed
attribute( 'color', 'vec3' );

// typed from primitive class
attribute( 'color', vec3 );

[LeviPesin]

It can handle attribute( 'color' ) (if make that change), attribute( 'color', 'vec3' ) and attribute( 'color', vec3() ). Did not thought about attribute( 'color', vec3 ), but it can also be easily added.

[sunag]

Did not thought about attribute( 'color', vec3 ), but it can also be easily added.

Nice, is better use attribute( 'color', vec3 ) instead of attribute( 'color', vec3() ) because it's not allocate unnecessary object in memory. attribute( 'color', vec3() ) shouldn't have support.