308 lines
		
	
	
		
			6.0 KiB
		
	
	
	
		
			JavaScript
		
	
	
	
	
	
		
		
			
		
	
	
			308 lines
		
	
	
		
			6.0 KiB
		
	
	
	
		
			JavaScript
		
	
	
	
	
	
|  | import { | ||
|  | 	BufferGeometry, | ||
|  | 	Color, | ||
|  | 	Float32BufferAttribute, | ||
|  | 	Vector2, | ||
|  | 	Vector3 | ||
|  | } from 'three'; | ||
|  | 
 | ||
|  | /** | ||
|  |  * Break faces with edges longer than maxEdgeLength | ||
|  |  */ | ||
|  | 
 | ||
|  | class TessellateModifier { | ||
|  | 
 | ||
|  | 	constructor( maxEdgeLength = 0.1, maxIterations = 6 ) { | ||
|  | 
 | ||
|  | 		this.maxEdgeLength = maxEdgeLength; | ||
|  | 		this.maxIterations = maxIterations; | ||
|  | 
 | ||
|  | 	} | ||
|  | 
 | ||
|  | 	modify( geometry ) { | ||
|  | 
 | ||
|  | 		if ( geometry.index !== null ) { | ||
|  | 
 | ||
|  | 			geometry = geometry.toNonIndexed(); | ||
|  | 
 | ||
|  | 		} | ||
|  | 
 | ||
|  | 		//
 | ||
|  | 
 | ||
|  | 		const maxIterations = this.maxIterations; | ||
|  | 		const maxEdgeLengthSquared = this.maxEdgeLength * this.maxEdgeLength; | ||
|  | 
 | ||
|  | 		const va = new Vector3(); | ||
|  | 		const vb = new Vector3(); | ||
|  | 		const vc = new Vector3(); | ||
|  | 		const vm = new Vector3(); | ||
|  | 		const vs = [ va, vb, vc, vm ]; | ||
|  | 
 | ||
|  | 		const na = new Vector3(); | ||
|  | 		const nb = new Vector3(); | ||
|  | 		const nc = new Vector3(); | ||
|  | 		const nm = new Vector3(); | ||
|  | 		const ns = [ na, nb, nc, nm ]; | ||
|  | 
 | ||
|  | 		const ca = new Color(); | ||
|  | 		const cb = new Color(); | ||
|  | 		const cc = new Color(); | ||
|  | 		const cm = new Color(); | ||
|  | 		const cs = [ ca, cb, cc, cm ]; | ||
|  | 
 | ||
|  | 		const ua = new Vector2(); | ||
|  | 		const ub = new Vector2(); | ||
|  | 		const uc = new Vector2(); | ||
|  | 		const um = new Vector2(); | ||
|  | 		const us = [ ua, ub, uc, um ]; | ||
|  | 
 | ||
|  | 		const u2a = new Vector2(); | ||
|  | 		const u2b = new Vector2(); | ||
|  | 		const u2c = new Vector2(); | ||
|  | 		const u2m = new Vector2(); | ||
|  | 		const u2s = [ u2a, u2b, u2c, u2m ]; | ||
|  | 
 | ||
|  | 		const attributes = geometry.attributes; | ||
|  | 		const hasNormals = attributes.normal !== undefined; | ||
|  | 		const hasColors = attributes.color !== undefined; | ||
|  | 		const hasUVs = attributes.uv !== undefined; | ||
|  | 		const hasUV1s = attributes.uv1 !== undefined; | ||
|  | 
 | ||
|  | 		let positions = attributes.position.array; | ||
|  | 		let normals = hasNormals ? attributes.normal.array : null; | ||
|  | 		let colors = hasColors ? attributes.color.array : null; | ||
|  | 		let uvs = hasUVs ? attributes.uv.array : null; | ||
|  | 		let uv1s = hasUV1s ? attributes.uv1.array : null; | ||
|  | 
 | ||
|  | 		let positions2 = positions; | ||
|  | 		let normals2 = normals; | ||
|  | 		let colors2 = colors; | ||
|  | 		let uvs2 = uvs; | ||
|  | 		let uv1s2 = uv1s; | ||
|  | 
 | ||
|  | 		let iteration = 0; | ||
|  | 		let tessellating = true; | ||
|  | 
 | ||
|  | 		function addTriangle( a, b, c ) { | ||
|  | 
 | ||
|  | 			const v1 = vs[ a ]; | ||
|  | 			const v2 = vs[ b ]; | ||
|  | 			const v3 = vs[ c ]; | ||
|  | 
 | ||
|  | 			positions2.push( v1.x, v1.y, v1.z ); | ||
|  | 			positions2.push( v2.x, v2.y, v2.z ); | ||
|  | 			positions2.push( v3.x, v3.y, v3.z ); | ||
|  | 
 | ||
|  | 			if ( hasNormals ) { | ||
|  | 
 | ||
|  | 				const n1 = ns[ a ]; | ||
|  | 				const n2 = ns[ b ]; | ||
|  | 				const n3 = ns[ c ]; | ||
|  | 
 | ||
|  | 				normals2.push( n1.x, n1.y, n1.z ); | ||
|  | 				normals2.push( n2.x, n2.y, n2.z ); | ||
|  | 				normals2.push( n3.x, n3.y, n3.z ); | ||
|  | 
 | ||
|  | 			} | ||
|  | 
 | ||
|  | 			if ( hasColors ) { | ||
|  | 
 | ||
|  | 				const c1 = cs[ a ]; | ||
|  | 				const c2 = cs[ b ]; | ||
|  | 				const c3 = cs[ c ]; | ||
|  | 
 | ||
|  | 				colors2.push( c1.r, c1.g, c1.b ); | ||
|  | 				colors2.push( c2.r, c2.g, c2.b ); | ||
|  | 				colors2.push( c3.r, c3.g, c3.b ); | ||
|  | 
 | ||
|  | 			} | ||
|  | 
 | ||
|  | 			if ( hasUVs ) { | ||
|  | 
 | ||
|  | 				const u1 = us[ a ]; | ||
|  | 				const u2 = us[ b ]; | ||
|  | 				const u3 = us[ c ]; | ||
|  | 
 | ||
|  | 				uvs2.push( u1.x, u1.y ); | ||
|  | 				uvs2.push( u2.x, u2.y ); | ||
|  | 				uvs2.push( u3.x, u3.y ); | ||
|  | 
 | ||
|  | 			} | ||
|  | 
 | ||
|  | 			if ( hasUV1s ) { | ||
|  | 
 | ||
|  | 				const u21 = u2s[ a ]; | ||
|  | 				const u22 = u2s[ b ]; | ||
|  | 				const u23 = u2s[ c ]; | ||
|  | 
 | ||
|  | 				uv1s2.push( u21.x, u21.y ); | ||
|  | 				uv1s2.push( u22.x, u22.y ); | ||
|  | 				uv1s2.push( u23.x, u23.y ); | ||
|  | 
 | ||
|  | 			} | ||
|  | 
 | ||
|  | 		} | ||
|  | 
 | ||
|  | 		while ( tessellating && iteration < maxIterations ) { | ||
|  | 
 | ||
|  | 			iteration ++; | ||
|  | 			tessellating = false; | ||
|  | 
 | ||
|  | 			positions = positions2; | ||
|  | 			positions2 = []; | ||
|  | 
 | ||
|  | 			if ( hasNormals ) { | ||
|  | 
 | ||
|  | 				normals = normals2; | ||
|  | 				normals2 = []; | ||
|  | 
 | ||
|  | 			} | ||
|  | 
 | ||
|  | 			if ( hasColors ) { | ||
|  | 
 | ||
|  | 				colors = colors2; | ||
|  | 				colors2 = []; | ||
|  | 
 | ||
|  | 			} | ||
|  | 
 | ||
|  | 			if ( hasUVs ) { | ||
|  | 
 | ||
|  | 				uvs = uvs2; | ||
|  | 				uvs2 = []; | ||
|  | 
 | ||
|  | 			} | ||
|  | 
 | ||
|  | 			if ( hasUV1s ) { | ||
|  | 
 | ||
|  | 				uv1s = uv1s2; | ||
|  | 				uv1s2 = []; | ||
|  | 
 | ||
|  | 			} | ||
|  | 
 | ||
|  | 			for ( let i = 0, i2 = 0, il = positions.length; i < il; i += 9, i2 += 6 ) { | ||
|  | 
 | ||
|  | 				va.fromArray( positions, i + 0 ); | ||
|  | 				vb.fromArray( positions, i + 3 ); | ||
|  | 				vc.fromArray( positions, i + 6 ); | ||
|  | 
 | ||
|  | 				if ( hasNormals ) { | ||
|  | 
 | ||
|  | 					na.fromArray( normals, i + 0 ); | ||
|  | 					nb.fromArray( normals, i + 3 ); | ||
|  | 					nc.fromArray( normals, i + 6 ); | ||
|  | 
 | ||
|  | 				} | ||
|  | 
 | ||
|  | 				if ( hasColors ) { | ||
|  | 
 | ||
|  | 					ca.fromArray( colors, i + 0 ); | ||
|  | 					cb.fromArray( colors, i + 3 ); | ||
|  | 					cc.fromArray( colors, i + 6 ); | ||
|  | 
 | ||
|  | 				} | ||
|  | 
 | ||
|  | 				if ( hasUVs ) { | ||
|  | 
 | ||
|  | 					ua.fromArray( uvs, i2 + 0 ); | ||
|  | 					ub.fromArray( uvs, i2 + 2 ); | ||
|  | 					uc.fromArray( uvs, i2 + 4 ); | ||
|  | 
 | ||
|  | 				} | ||
|  | 
 | ||
|  | 				if ( hasUV1s ) { | ||
|  | 
 | ||
|  | 					u2a.fromArray( uv1s, i2 + 0 ); | ||
|  | 					u2b.fromArray( uv1s, i2 + 2 ); | ||
|  | 					u2c.fromArray( uv1s, i2 + 4 ); | ||
|  | 
 | ||
|  | 				} | ||
|  | 
 | ||
|  | 				const dab = va.distanceToSquared( vb ); | ||
|  | 				const dbc = vb.distanceToSquared( vc ); | ||
|  | 				const dac = va.distanceToSquared( vc ); | ||
|  | 
 | ||
|  | 				if ( dab > maxEdgeLengthSquared || dbc > maxEdgeLengthSquared || dac > maxEdgeLengthSquared ) { | ||
|  | 
 | ||
|  | 					tessellating = true; | ||
|  | 
 | ||
|  | 					if ( dab >= dbc && dab >= dac ) { | ||
|  | 
 | ||
|  | 						vm.lerpVectors( va, vb, 0.5 ); | ||
|  | 						if ( hasNormals ) nm.lerpVectors( na, nb, 0.5 ); | ||
|  | 						if ( hasColors ) cm.lerpColors( ca, cb, 0.5 ); | ||
|  | 						if ( hasUVs ) um.lerpVectors( ua, ub, 0.5 ); | ||
|  | 						if ( hasUV1s ) u2m.lerpVectors( u2a, u2b, 0.5 ); | ||
|  | 
 | ||
|  | 						addTriangle( 0, 3, 2 ); | ||
|  | 						addTriangle( 3, 1, 2 ); | ||
|  | 
 | ||
|  | 					} else if ( dbc >= dab && dbc >= dac ) { | ||
|  | 
 | ||
|  | 						vm.lerpVectors( vb, vc, 0.5 ); | ||
|  | 						if ( hasNormals ) nm.lerpVectors( nb, nc, 0.5 ); | ||
|  | 						if ( hasColors ) cm.lerpColors( cb, cc, 0.5 ); | ||
|  | 						if ( hasUVs ) um.lerpVectors( ub, uc, 0.5 ); | ||
|  | 						if ( hasUV1s ) u2m.lerpVectors( u2b, u2c, 0.5 ); | ||
|  | 
 | ||
|  | 						addTriangle( 0, 1, 3 ); | ||
|  | 						addTriangle( 3, 2, 0 ); | ||
|  | 
 | ||
|  | 					} else { | ||
|  | 
 | ||
|  | 						vm.lerpVectors( va, vc, 0.5 ); | ||
|  | 						if ( hasNormals ) nm.lerpVectors( na, nc, 0.5 ); | ||
|  | 						if ( hasColors ) cm.lerpColors( ca, cc, 0.5 ); | ||
|  | 						if ( hasUVs ) um.lerpVectors( ua, uc, 0.5 ); | ||
|  | 						if ( hasUV1s ) u2m.lerpVectors( u2a, u2c, 0.5 ); | ||
|  | 
 | ||
|  | 						addTriangle( 0, 1, 3 ); | ||
|  | 						addTriangle( 3, 1, 2 ); | ||
|  | 
 | ||
|  | 					} | ||
|  | 
 | ||
|  | 				} else { | ||
|  | 
 | ||
|  | 					addTriangle( 0, 1, 2 ); | ||
|  | 
 | ||
|  | 				} | ||
|  | 
 | ||
|  | 			} | ||
|  | 
 | ||
|  | 		} | ||
|  | 
 | ||
|  | 		const geometry2 = new BufferGeometry(); | ||
|  | 
 | ||
|  | 		geometry2.setAttribute( 'position', new Float32BufferAttribute( positions2, 3 ) ); | ||
|  | 
 | ||
|  | 		if ( hasNormals ) { | ||
|  | 
 | ||
|  | 			geometry2.setAttribute( 'normal', new Float32BufferAttribute( normals2, 3 ) ); | ||
|  | 
 | ||
|  | 		} | ||
|  | 
 | ||
|  | 		if ( hasColors ) { | ||
|  | 
 | ||
|  | 			geometry2.setAttribute( 'color', new Float32BufferAttribute( colors2, 3 ) ); | ||
|  | 
 | ||
|  | 		} | ||
|  | 
 | ||
|  | 		if ( hasUVs ) { | ||
|  | 
 | ||
|  | 			geometry2.setAttribute( 'uv', new Float32BufferAttribute( uvs2, 2 ) ); | ||
|  | 
 | ||
|  | 		} | ||
|  | 
 | ||
|  | 		if ( hasUV1s ) { | ||
|  | 
 | ||
|  | 			geometry2.setAttribute( 'uv1', new Float32BufferAttribute( uv1s2, 2 ) ); | ||
|  | 
 | ||
|  | 		} | ||
|  | 
 | ||
|  | 		return geometry2; | ||
|  | 
 | ||
|  | 	} | ||
|  | 
 | ||
|  | } | ||
|  | 
 | ||
|  | export { TessellateModifier }; |