NodeMaterial & WebGPU: Revision of Lighting Model System

[sunag]

Description

We have a much more solid system for creating Lighting Models, WebGPURenderer is completely based on nodes, this means that you can create new materials and new light types, modular and tree-shaking so that we don't have to of hacks ever again :)

MeshStandardNodeMaterial

 class MeshStandardNodeMaterial extends NodeMaterial {

	constructLightingModel( /*builder*/ ) {

		return physicalLightingModel;

	}

	constructVariants( builder, stack ) {

		// METALNESS

		let metalnessNode = this.metalnessNode ? float( this.metalnessNode ) : materialMetalness;

		stack.assign( metalness, metalnessNode );
		stack.assign( diffuseColor, vec4( diffuseColor.rgb.mul( metalnessNode.invert() ), diffuseColor.a ) );

		// ROUGHNESS

		let roughnessNode = this.roughnessNode ? float( this.roughnessNode ) : materialRoughness;
		roughnessNode = getRoughness.call( { roughness: roughnessNode } );

		stack.assign( roughness, roughnessNode );

		// SPECULAR COLOR

		const specularColorNode = mix( vec3( 0.04 ), materialColor.rgb, metalnessNode );

		stack.assign( specularColor, specularColorNode );

	}

}

MeshPhongNodeMaterial

 class MeshPhongNodeMaterial extends NodeMaterial {

	constructLightingModel( /*builder*/ ) {

		return phongLightingModel;

	}

	constructVariants( builder, stack ) {

		// SHININESS

		const shininessNode = float( this.shininessNode || materialShininess ).max( 1e-4 ); // to prevent pow( 0.0, 0.0 )

		stack.assign( shininess, shininessNode );

		// SPECULAR COLOR

		const specularNode = vec3( this.specularNode || materialSpecularColor );

		stack.assign( specularColor, specularNode );

	}

}

Highlights

• Added webgpu phong example
• Revised lighting system and added Phong Model Lighting
• Add DiscardNode
• Add LightingModel class
• MaterialNode: Add UV, SHININESS, SPECULAR_COLOR, REFLECTIVITY
• Added ExtendedMaterialNode
• CondNode: Support to use of "if" only and "void"
• ExpressionNode: Fix if used with "void" type
• StackNode: new add() method
• NodeBuilder: Non-breakline supports
• Rename exp2Fog to densityFog
• NodeMaterial: Renamed .generate() to .construct*() following Node design.
• Added stack.assign() instead of builder.addFlow( 'fragment', ... )

This contribution is funded by Google via Igalia

[sunag]

I updated the description.