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Merged
merged 1 commit into from
Oct 5, 2021
Merged

MarchingCubes: Migrate to Mesh. #22642

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196 changes: 45 additions & 151 deletions examples/jsm/objects/MarchingCubes.js
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Original file line number Diff line number Diff line change
Expand Up @@ -2,19 +2,21 @@ import {
BufferAttribute,
BufferGeometry,
Color,
ImmediateRenderObject,
NoColors
DynamicDrawUsage,
Mesh
} from '../../../build/three.module.js';

/**
* Port of http://webglsamples.org/blob/blob.html
*/

class MarchingCubes extends ImmediateRenderObject {
class MarchingCubes extends Mesh {

constructor( resolution, material, enableUvs, enableColors ) {
constructor( resolution, material, enableUvs = false, enableColors = false, maxPolyCount = 10000 ) {

super( material );
const geometry = new BufferGeometry();

super( geometry, material );

const scope = this;

Expand All @@ -24,8 +26,8 @@ class MarchingCubes extends ImmediateRenderObject {
const nlist = new Float32Array( 12 * 3 );
const clist = new Float32Array( 12 * 3 );

this.enableUvs = enableUvs !== undefined ? enableUvs : false;
this.enableColors = enableColors !== undefined ? enableColors : false;
this.enableUvs = enableUvs;
this.enableColors = enableColors;

// functions have to be object properties
// prototype functions kill performance
Expand Down Expand Up @@ -56,28 +58,37 @@ class MarchingCubes extends ImmediateRenderObject {
this.normal_cache = new Float32Array( this.size3 * 3 );
this.palette = new Float32Array( this.size3 * 3 );

// immediate render mode simulator
//

this.maxCount = 4096; // TODO: find the fastest size for this buffer
this.count = 0;

this.hasPositions = false;
this.hasNormals = false;
this.hasColors = false;
this.hasUvs = false;
const maxVertexCount = maxPolyCount * 3;

this.positionArray = new Float32Array( maxVertexCount * 3 );
const positionAttribute = new BufferAttribute( this.positionArray, 3 );
positionAttribute.setUsage( DynamicDrawUsage );
geometry.setAttribute( 'position', positionAttribute );

this.positionArray = new Float32Array( this.maxCount * 3 );
this.normalArray = new Float32Array( this.maxCount * 3 );
this.normalArray = new Float32Array( maxVertexCount * 3 );
const normalAttribute = new BufferAttribute( this.normalArray, 3 );
normalAttribute.setUsage( DynamicDrawUsage );
geometry.setAttribute( 'normal', normalAttribute );

if ( this.enableUvs ) {

this.uvArray = new Float32Array( this.maxCount * 2 );
this.uvArray = new Float32Array( maxVertexCount * 2 );
const uvAttribute = new BufferAttribute( this.uvArray, 2 );
uvAttribute.setUsage( DynamicDrawUsage );
geometry.setAttribute( 'uv', uvAttribute );

}

if ( this.enableColors ) {

this.colorArray = new Float32Array( this.maxCount * 3 );
this.colorArray = new Float32Array( maxVertexCount * 3 );
const colorAttribute = new BufferAttribute( this.colorArray, 3 );
colorAttribute.setUsage( DynamicDrawUsage );
geometry.setAttribute( 'color', colorAttribute );

}

Expand Down Expand Up @@ -173,7 +184,7 @@ class MarchingCubes extends ImmediateRenderObject {
// Returns total number of triangles. Fills triangles.
// (this is where most of time is spent - it's inner work of O(n3) loop )

function polygonize( fx, fy, fz, q, isol, renderCallback ) {
function polygonize( fx, fy, fz, q, isol ) {

// cache indices
const q1 = q + 1,
Expand Down Expand Up @@ -369,8 +380,7 @@ class MarchingCubes extends ImmediateRenderObject {
clist,
3 * triTable[ o1 ],
3 * triTable[ o2 ],
3 * triTable[ o3 ],
renderCallback
3 * triTable[ o3 ]
);

i += 3;
Expand All @@ -382,11 +392,7 @@ class MarchingCubes extends ImmediateRenderObject {

}

/////////////////////////////////////
// Immediate render mode simulator
/////////////////////////////////////

function posnormtriv( pos, norm, colors, o1, o2, o3, renderCallback ) {
function posnormtriv( pos, norm, colors, o1, o2, o3 ) {

const c = scope.count * 3;

Expand Down Expand Up @@ -477,69 +483,8 @@ class MarchingCubes extends ImmediateRenderObject {

scope.count += 3;

if ( scope.count >= scope.maxCount - 3 ) {

scope.hasPositions = true;
scope.hasNormals = true;

if ( scope.enableUvs ) {

scope.hasUvs = true;

}

if ( scope.enableColors ) {

scope.hasColors = true;

}

renderCallback( scope );

}

}

this.begin = function () {

this.count = 0;

this.hasPositions = false;
this.hasNormals = false;
this.hasUvs = false;
this.hasColors = false;

};

this.end = function ( renderCallback ) {

if ( this.count === 0 ) return;

for ( let i = this.count * 3; i < this.positionArray.length; i ++ ) {

this.positionArray[ i ] = 0.0;

}

this.hasPositions = true;
this.hasNormals = true;

if ( this.enableUvs && this.material.map ) {

this.hasUvs = true;

}

if ( this.enableColors && this.material.vertexColors !== NoColors ) {

this.hasColors = true;

}

renderCallback( this );

};

/////////////////////////////////////
// Metaballs
/////////////////////////////////////
Expand Down Expand Up @@ -867,9 +812,9 @@ class MarchingCubes extends ImmediateRenderObject {

};

this.render = function ( renderCallback ) {
this.onBeforeRender = function () {

this.begin();
this.count = 0;

// Triangulate. Yeah, this is slow.

Expand All @@ -890,84 +835,33 @@ class MarchingCubes extends ImmediateRenderObject {
const fx = ( x - this.halfsize ) / this.halfsize; //+ 1
const q = y_offset + x;

polygonize( fx, fy, fz, q, this.isolation, renderCallback );
polygonize( fx, fy, fz, q, this.isolation );

}

}

}

this.end( renderCallback );
// reset unneeded data

};
for ( let i = this.count * 3; i < this.positionArray.length; i ++ ) {

this.generateGeometry = function () {
this.positionArray[ i ] = 0.0;
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Collaborator Author

@Mugen87 Mugen87 Oct 5, 2021

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Instead of resetting the vertices like before, I was trying to use setDrawRange() to limit the rendered data, However, this introduces strange flickering (it seems the number of rendered triangles varies from frame to frame). Hence, I've sticked to the previous approach for now.


console.warn(
'THREE.MarchingCubes: generateGeometry() now returns BufferGeometry'
);
return this.generateBufferGeometry();
}

};
// update geometry data

function concatenate( a, b, length ) {
geometry.getAttribute( 'position' ).needsUpdate = true;
geometry.getAttribute( 'normal' ).needsUpdate = true;

const result = new Float32Array( a.length + length );
result.set( a, 0 );
result.set( b.slice( 0, length ), a.length );
return result;
if ( this.enableUvs ) geometry.getAttribute( 'uv' ).needsUpdate = true;
if ( this.enableColors ) geometry.getAttribute( 'color' ).needsUpdate = true;

}
// safety check

this.generateBufferGeometry = function () {

const geo = new BufferGeometry();
let posArray = new Float32Array();
let normArray = new Float32Array();
let colorArray = new Float32Array();
let uvArray = new Float32Array();
const scope = this;

const geo_callback = function ( object ) {

if ( scope.hasPositions )
posArray = concatenate(
posArray,
object.positionArray,
object.count * 3
);
if ( scope.hasNormals )
normArray = concatenate(
normArray,
object.normalArray,
object.count * 3
);
if ( scope.hasColors )
colorArray = concatenate(
colorArray,
object.colorArray,
object.count * 3
);
if ( scope.hasUvs )
uvArray = concatenate( uvArray, object.uvArray, object.count * 2 );

object.count = 0;

};

this.render( geo_callback );

if ( this.hasPositions )
geo.setAttribute( 'position', new BufferAttribute( posArray, 3 ) );
if ( this.hasNormals )
geo.setAttribute( 'normal', new BufferAttribute( normArray, 3 ) );
if ( this.hasColors )
geo.setAttribute( 'color', new BufferAttribute( colorArray, 3 ) );
if ( this.hasUvs )
geo.setAttribute( 'uv', new BufferAttribute( uvArray, 2 ) );

return geo;
if ( this.count / 3 > maxPolyCount ) console.warn( 'THREE.MarchingCubes: Geometry buffers too small for rendering. Please create an instance with a higher poly count.' );

};

Expand Down
2 changes: 1 addition & 1 deletion examples/webxr_vr_sculpt.html
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Original file line number Diff line number Diff line change
Expand Up @@ -157,7 +157,7 @@
transparent: true
} );

blob = new MarchingCubes( 64, material );
blob = new MarchingCubes( 64, material, false, false, 500000 );
blob.position.y = 1;
scene.add( blob );

Expand Down