把一个圆柱体打到3。

I'm looking after this for a long time now. I just can't find any solution, anywhere. I'm trying to apply 3 different textures on a cylinder (2 caps, and side) But I have absolutely no idea on how to achieve this. Can you orient me? Here's what I'm doing for now :

我现在很长时间都在关注这个问题。我在任何地方都找不到解决办法。我试着用三种不同的材质在一个圆柱体上(2个瓶盖和侧面)，但是我完全不知道如何做到这一点。你能引导我吗?这就是我现在要做的:

var coin1_geo = new THREE.CylinderGeometry( 100, 100, 10, 100, 100, false );
var coin1_texture = THREE.ImageUtils.loadTexture("./assets/avers.png");
var coin1_mat = new THREE.MeshLambertMaterial({map:coin1_texture});
var coin1 = new THREE.Mesh( coin1_geo, coin1_mat );
coin1.rotation.x = 20;
coin1.position.set(0,0,0);
coin1.castShadow = true;
coin1.receiveShadow = false;
scene.add( coin1 );

As you can see here, I only apply one texture on all faces. But even on caps, it's not really displaying, I only have a piece of the full circle. Please help, I'm achieving a coin, if you didn't figure out. Even if you just give me a link to a tutorial I would be really thanksfull. I can't find anything, and my knowledge in 3D/OpenGL programming is quite limited. Thanks a lot.

正如你在这里看到的，我只在所有的面上应用一个纹理。但即使是大写，也不是真正的显示，我只有一个完整的圆。请帮忙，如果你不知道的话，我正在取得一枚硬币。即使你给我一个教程链接，我也会非常感谢。我找不到任何东西，而且我在3D/OpenGL编程方面的知识非常有限。非常感谢。

1 个解决方案

#1

[edit] Three cylinders didn't work since the cap UVs are bogus. You need to roll your own cap geometries. Not a lot of work, just annoying. Here's how to do an uncapped cylinder with custom caps:

[编辑]3个汽缸没有工作，因为上限UVs是假的。你需要滚动你自己的帽子几何图形。不是很多工作，只是烦人。下面是如何使用自定义大写的无上限圆筒:

var coin_sides_geo =
  new THREE.CylinderGeometry( 10.0, 10.0, 1.0, 100.0, 10.0, true );
var coin_cap_geo = new THREE.Geometry();
var r = 10.0;
for (var i=0; i<100; i++) {
  var a = i * 1/100 * Math.PI * 2;
  var z = Math.sin(a);
  var x = Math.cos(a);
  var a1 = (i+1) * 1/100 * Math.PI * 2;
  var z1 = Math.sin(a1);
  var x1 = Math.cos(a1);
  coin_cap_geo.vertices.push(
    new THREE.Vertex(new THREE.Vector3(0, 0, 0)),
    new THREE.Vertex(new THREE.Vector3(x*r, 0, z*r)),
    new THREE.Vertex(new THREE.Vector3(x1*r, 0, z1*r))
  );
  coin_cap_geo.faceVertexUvs[0].push([
    new THREE.UV(0.5, 0.5),
    new THREE.UV(x/2+0.5, z/2+0.5),
    new THREE.UV(x1/2+0.5, z1/2+0.5)
  ]);
  coin_cap_geo.faces.push(new THREE.Face3(i*3, i*3+1, i*3+2));
}
coin_cap_geo.computeCentroids();
coin_cap_geo.computeFaceNormals();

var coin_sides_texture =
  THREE.ImageUtils.loadTexture("./coin_sides.png");
var coin_cap_texture =
  THREE.ImageUtils.loadTexture("./coin_face.png");

var coin_sides_mat =
  new THREE.MeshLambertMaterial({map:coin_sides_texture});
var coin_sides =
  new THREE.Mesh( coin_sides_geo, coin_sides_mat );

var coin_cap_mat = new THREE.MeshLambertMaterial({map:coin_cap_texture});
var coin_cap_top = new THREE.Mesh( coin_cap_geo, coin_cap_mat );
var coin_cap_bottom = new THREE.Mesh( coin_cap_geo, coin_cap_mat );
coin_cap_top.position.y = 0.5;
coin_cap_bottom.position.y = -0.5;
coin_cap_top.rotation.x = Math.PI;

var coin = new THREE.Object3D();
coin.add(coin_sides);
coin.add(coin_cap_top);
coin.add(coin_cap_bottom);