挤出具有多个孔的多个多边形并对组合形状进行纹理化 [英] Extruding multiple polygons with multiple holes and texturing the combined shape
问题描述
这个问题与这个，但因为出现频率最高的词是todo"，所以也帮不上什么忙.而且我是three.js的新手，我认为这对于一些有经验的three.js用户来说可能是微不足道的任务.
更新:为了确保孔多边形始终表现良好，这意味着孔多边形始终完全位于材料多边形内，并且材料多边形或孔中没有重复的顶点或自相交-多边形和所有材料多边形的缠绕顺序为 CW，孔为 CCW.
更新:合并几何图形不是对由一个纹理设置的整个挤出多边形进行纹理化的解决方案:http://jsfiddle.净/C5dga.纹理在所有单个形状上重复，因此在这种情况下合并几何图形没有实际意义.在挤压之前合并形状可能会找到解决方案，但尚未找到解决方案.
您可以按照以下代码段合并几何图形，从而只生成一个网格.从您之前的问题中，您已经知道如何对单个几何体进行纹理处理.
var geometry1 = new THREE.ExtrudeGeometry(shape1,extrudeSettings);var geometry2 = new THREE.ExtrudeGeometry(shape2,extrudeSettings);几何1.合并(几何2)；...var mesh = new THREE.Mesh(geometry1, material);场景添加(网格)；小提琴:http://jsfiddle.net/pHn2B/88/
小提琴:http://jsfiddle.net/C5dga/13/(带纹理)
作为创建单独几何图形和使用 merge 实用程序的替代方法，您可以使用以下模式创建单个几何图形:
var geometry1 = new THREE.ExtrudeGeometry( [ shape1, shape2 ],extrudeSettings );更新为three.js r.70
This question is related to this question. The answer shows very nice way to extrude polygons that have holes (see the excellent live example). The main learning of the answer was that paths in three.js (r58) cannot have more than one moveTo command and it have to be in the start of the path, which means that path have to be broken by moveTos, so that moveTo start always a new path.
Extruding in three.js means that 2D paths are converted to 3D shapes using possible beveling. It is suitable for extruding texts to make 3D letters and words, but can be used also to extrude custom paths.
Now there arises two questions:
- how is it possible to handle polygons that have multiple hole-polygons and multiple non-hole-polygons?
- how is it possible to add a texture to generated shape as a whole?
I made an example of this as SVG in http://jsbin.com/oqomuj/1/edit:
The image is produced using this path:
<path d=" M57.11,271.77 L57.11,218.33 L41.99,218.63 L105.49,165.77 L138.41,193.18 L138.41,172.2 L152.53,172.2 L152.53,204.93 L168.99,218.63 L153.21,218.63 L153.21,271.77Z M74.14,264.13 L105.49,264.13 L105.49,232.8 L74.14,232.8Z M115.35,250.7 L135.96,250.7 L135.96,232.61 L115.35,232.61Z M56.11,145.77 L56.11,92.33 L40.99,92.63 L104.49,39.77 L137.41,67.18 L137.41,46.2 L151.53,46.2 L151.53,78.93 L152.53,79.76 L155.55,77.23 L159.5,74.52 L168.65,69.81 L176.46,66.93 L188.04,64.16 L200.63,62.7 L213.65,62.7 L226.05,64.09 L234.83,66.06 L245.65,69.73 L252.87,73.27 L259.12,77.34 L262.63,80.33 L265.6,83.47 L268.01,86.76 L269.83,90.17 L271.08,93.68 L271.76,99.08 L271.04,104.64 L269.75,108.2 L267.87,111.63 L265.42,114.91 L262.44,118.01 L258.95,120.92 L255.02,123.63 L245.86,128.34 L238.06,131.22 L226.48,133.99 L213.88,135.44 L200.63,135.44 L188.04,133.99 L176.46,131.22 L168.65,128.34 L159.5,123.63 L155.55,120.92 L152.21,118.12 L152.21,145.77Z M73.14,138.13 L104.49,138.13 L104.49,106.8 L73.14,106.8Z M114.35,124.7 L134.96,124.7 L134.96,106.61 L114.35,106.61Z M207.26,117.33 L210.57,117.26 L216.87,116.53 L222.66,115.15 L227.8,113.18 L233.11,110 L236.34,106.99 L238.51,103.64 L239.42,100.48 L239.42,97.67 L238.51,94.51 L236.34,91.16 L233.11,88.15 L227.8,84.97 L222.66,83 L216.87,81.62 L210.57,80.89 L203.94,80.89 L197.65,81.62 L191.86,83 L186.71,84.97 L181.41,88.15 L178.18,91.16 L176.01,94.51 L175.1,97.67 L175.1,100.48 L176.01,103.64 L178.18,106.99 L181.41,110 L186.71,113.18 L191.86,115.15 L197.65,116.53 L203.94,117.26Z "></path>
and this path converted to individual arrays of vertices:
var lower_house_material = [{x:57.11,y:271.77},{x:57.11,y:218.33},{x:41.99,y:218.63},{x:105.49,y:165.77},{x:138.42,y:193.18},{x:138.42,y:172.2},{x:152.53,y:172.2},{x:152.53,y:204.93},{x:168.99,y:218.63},{x:153.21,y:218.63},{x:153.21,y:271.77}];
var lower_house_hole_1 = [{x:74.14,y:264.13},{x:105.49,y:264.13},{x:105.49,y:232.8},{x:74.14,y:232.8}];
var lower_house_hole_2 = [{x:115.35,y:250.7},{x:135.96,y:250.7},{x:135.96,y:232.61},{x:115.35,y:232.61}];
var upper_house_material = [{x:56.11,y:145.77},{x:56.11,y:92.33},{x:40.99,y:92.63},{x:104.49,y:39.77},{x:137.42,y:67.18},{x:137.42,y:46.2},{x:151.53,y:46.2},{x:151.53,y:78.93},{x:152.53,y:79.76},{x:155.55,y:77.23},{x:159.5,y:74.52},{x:168.65,y:69.81},{x:176.46,y:66.93},{x:188.04,y:64.16},{x:200.63,y:62.7},{x:213.65,y:62.7},{x:226.05,y:64.1},{x:234.83,y:66.06},{x:245.65,y:69.73},{x:252.87,y:73.27},{x:259.12,y:77.35},{x:262.63,y:80.33},{x:265.6,y:83.47},{x:268.01,y:86.76},{x:269.84,y:90.17},{x:271.08,y:93.68},{x:271.76,y:99.08},{x:271.04,y:104.64},{x:269.75,y:108.2},{x:267.87,y:111.63},{x:265.42,y:114.91},{x:262.44,y:118.01},{x:258.96,y:120.92},{x:255.02,y:123.63},{x:245.86,y:128.34},{x:238.06,y:131.22},{x:226.48,y:133.99},{x:213.88,y:135.45},{x:200.63,y:135.45},{x:188.04,y:133.99},{x:176.46,y:131.22},{x:168.65,y:128.34},{x:159.5,y:123.63},{x:155.55,y:120.92},{x:152.21,y:118.12},{x:152.21,y:145.77}];
var upper_house_hole_1 = [{x:73.14,y:138.13},{x:104.49,y:138.13},{x:104.49,y:106.8},{x:73.14,y:106.8}];
var upper_house_hole_2 = [{x:114.35,y:124.7},{x:134.96,y:124.7},{x:134.96,y:106.61},{x:114.35,y:106.61}];
var upper_house_hole_3 = [{x:207.26,y:117.33},{x:210.57,y:117.26},{x:216.87,y:116.53},{x:222.66,y:115.15},{x:227.8,y:113.18},{x:233.11,y:110},{x:236.34,y:106.99},{x:238.51,y:103.64},{x:239.42,y:100.48},{x:239.42,y:97.67},{x:238.51,y:94.51},{x:236.34,y:91.16},{x:233.11,y:88.15},{x:227.8,y:84.97},{x:222.66,y:83},{x:216.87,y:81.62},{x:210.57,y:80.89},{x:203.94,y:80.89},{x:197.65,y:81.62},{x:191.86,y:83},{x:186.71,y:84.97},{x:181.41,y:88.15},{x:178.18,y:91.16},{x:176.01,y:94.51},{x:175.1,y:97.67},{x:175.1,y:100.48},{x:176.01,y:103.64},{x:178.18,y:106.99},{x:181.41,y:110},{x:186.71,y:113.18},{x:191.86,y:115.15},{x:197.65,y:116.53},{x:203.94,y:117.26}];
The question is, how this like structure can be converted to 3D object in three.js so that it can be extruded using THREE.ExtrudeGeometry( shape, extrusionSettings ) and after that textured as a whole?
I can examine the path data to know what hole belongs to what polygon and handle all as separate shapes, but because I want to use one texture image across all the shapes, I think the preferred way is to handle all material-polygons as one shape, and hole-polygons as other shape and use something like:
var shape = [lower_house_material, upper_house_material]; shape.holes = [lower_house_hole_1, lower_house_hole_2, upper_house_hole_1, upper_house_hole_2, upper_house_hole_3]; var 3d_geometry = THREE.ExtrudeGeometry( shape, extrusionSettings );
So the 3d_geometry should be at the end one mesh to which I can append a texture this way:
var textureFront = new THREE.ImageUtils.loadTexture( 'textureFront.png');
var textureSide = new THREE.ImageUtils.loadTexture( 'textureSide.png');
var materialFront = new THREE.MeshBasicMaterial( { map: textureFront } );
var materialSide = new THREE.MeshBasicMaterial( { map: textureSide } );
var materialArray = [ materialFront, materialSide ];
var faceMaterial = new THREE.MeshFaceMaterial(materialArray);
var final_mesh = new THREE.Mesh(3d_geometry, faceMaterial );
And one of the textures could be something like this (256x256px):
And texture applied:
And because the mesh is extruded, there is also 3D thickness on the above, but you got the idea of texturing.
I know that y-coordinates have to be flipped but it is a trivial task and not the point of my question, but if three.js has ready-made function for clipping y, it would be helpful.
I have spent hours to examine the three.js source code, examples and documentation, but because the most frequent word there is "todo", it cannot help much. And I'm very newbie to three.js, I would think that this may be trivial task for some experienced three.js user.
UPDATE: And just to make sure, the hole polygons are always well-behaved, which means that hole polygons are always fully inside material-polygons and there are no duplicate vertices or self-intersections either in material-polygons or hole-polygons and all material-polygons have CW winding order and holes CCW.
UPDATE: Merging geometries was not a solution for texturing the whole extruded polygon set by one texture: http://jsfiddle.net/C5dga. The texture is repeated on all individual shapes, so merging geometries in this case has no real meaning. The solution could be possibly found on merging shapes before they are extruded, but not found solution for this yet.
You can merge geometries as in the following snippet, resulting in just a single mesh. From your prior questions, you already know how to texture a single geometry.
var geometry1 = new THREE.ExtrudeGeometry( shape1, extrusionSettings );
var geometry2 = new THREE.ExtrudeGeometry( shape2, extrusionSettings );
geometry1.merge( geometry2 );
. . .
var mesh = new THREE.Mesh( geometry1, material );
scene.add( mesh );
Fiddle: http://jsfiddle.net/pHn2B/88/
Fiddle: http://jsfiddle.net/C5dga/13/ (with texture)
EDIT: As an alternative to creating separate geometries and using the merge utility, you can create a single geometry using the following pattern, instead:
var geometry1 = new THREE.ExtrudeGeometry( [ shape1, shape2 ], extrusionSettings );
EDIT: updated to three.js r.70
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