topical media & game development
sample-webgl-share.js / js
/*
SceneJS allows a mesh to be collectively constructed by a hierarchy of multiple Geometry nodes, such that the root
Geometry defines arrays for positions and uv coordinates, while sub-Geometry's supply indexes to define primitives
(faces, lines etc). When a geometry is defined with positions but no indices, then child Geometry nodes are expected
to supply the indices.
This is a powerful technique for optimising static scenes, and is used in games such as Quake etc. It is also
neccessary for "multi-materials", where different materials/textures can be applied to different subsections of the
same mesh.
It may also be useful for switching representations of geometry - between wireframe and solid, for example.
This example constructs a custom cube from multiple geometries, decorating different faces with different textures.
github.com/xeolabs/scenejs/wiki/geometry
*/
SceneJS.createScene({
type: "scene",
id: "theScene",
canvasId: "theCanvas",
loggingElementId: "theLoggingDiv",
nodes: [
{
type: "lookAt",
eye : { x: 0.0, y: 10.0, z: -55 },
look : { y:1.0 },
up : { y: 1.0 },
nodes: [
{
type: "camera",
optics: {
type: "perspective",
fovy : 25.0,
aspect : 1.47,
near : 0.10,
far : 300.0
},
nodes: [
{
type: "light",
mode: "dir",
color: { r: 0.5, g: 0.5, b: 0.5 },
diffuse: true,
specular: true,
dir: { x: 1.0, y: 1.0, z: -1.0 }
},
{
type: "light",
mode: "dir",
color: { r: 0.7, g: 0.7, b: 0.7 },
diffuse: true,
specular: true,
dir: { x: 0.0, y: 1.0, z: -1.0 }
},
{
type: "light",
mode: "dir",
color: { r: 0.8, g: 0.8, b: 0.8 },
diffuse: true,
specular: true,
dir: { x: -1.0, y: 0.0, z: -1.0 }
},
/* Next, modelling transforms to orient our teapot
* by a given angle.
*/
{
type: "rotate",
id: "pitch",
angle: 0.0,
x : 1.0,
nodes: [
{
type: "rotate",
id: "yaw",
angle: 0.0,
y : 1.0,
nodes: [
Root Geometry defines vertex and uv arrays which are shared
among index arrays on sub-Geometry's
{
type: "geometry",
/* The vertices - eight for our cube, each
* one spanning three array elements for X,Y and Z
*/
positions : [
/* v0-v1-v2-v3 front
*/
5, 5, 5,
-5, 5, 5,
-5,-5, 5,
5,-5, 5,
/* v0-v3-v4-v5 right
*/
5, 5, 5,
5,-5, 5,
5,-5,-5,
5, 5,-5,
/* v0-v5-v6-v1 top
*/
5, 5, 5,
5, 5,-5,
-5, 5,-5,
-5, 5, 5,
/* v1-v6-v7-v2 left
*/
-5, 5, 5,
-5, 5,-5,
-5,-5,-5,
-5,-5, 5,
/* v7-v4-v3-v2 bottom
*/
-5,-5,-5,
5,-5,-5,
5,-5, 5,
-5,-5, 5,
/* v4-v7-v6-v5 back
*/
5,-5,-5,
-5,-5,-5,
-5, 5,-5,
5, 5,-5
],
/* Normal vectors, one for each vertex
*/
normals : [
/* v0-v1-v2-v3 front
*/
0, 0, -1,
0, 0, -1,
0, 0, -1,
0, 0, -1,
/* v0-v3-v4-v5 right
*/
-1, 0, 0,
-1, 0, 0,
-1, 0, 0,
-1, 0, 0,
/* v0-v5-v6-v1 top
*/
0, -1, 0,
0, -1, 0,
0, -1, 0,
0, -1, 0,
/* v1-v6-v7-v2 left
*/
1, 0, 0,
1, 0, 0,
1, 0, 0,
1, 0, 0,
/* v7-v4-v3-v2 bottom
*/
0,1, 0,
0,1, 0,
0,1, 0,
0,1, 0,
/* v4-v7-v6-v5 back
*/
0, 0,1,
0, 0,1,
0, 0,1,
0, 0,1
],
/* 2D texture coordinates corresponding to the
* 3D positions defined above - eight for our cube, each
* one spaining two array elements for X and Y
*/
uv : [
/* v0-v1-v2-v3 front
*/
5, 5,
0, 5,
0, 0,
5, 0,
/* v0-v3-v4-v5 right
*/
0, 5,
0, 0,
5, 0,
5, 5,
/* v0-v5-v6-v1 top
*/
5, 0,
5, 5,
0, 5,
0, 0,
/* v1-v6-v7-v2 left
*/
5, 5,
0, 5,
0, 0,
5, 0,
/* v7-v4-v3-v2 bottom
*/
0, 0,
5, 0,
5, 5,
0, 5,
/* v4-v7-v6-v5 back
*/
0, 0,
5, 0,
5, 5,
0, 5
],
nodes: [
{
type: "texture",
layers: [
{
uri:"@eye.gif" ,
minFilter: "linear",
magFilter: "linear",
wrapS: "repeat",
wrapT: "repeat",
isDepth: false,
depthMode:"luminance",
depthCompareMode: "compareRToTexture",
depthCompareFunc: "lequal",
flipY: false,
width: 1,
height: 1,
internalFormat:"lequal",
sourceFormat:"alpha",
sourceType: "unsignedByte",
applyTo:"baseColor",
blendMode: "multiply",
/* Texture rotation angle in degrees
*/
rotate: 0.0,
/* Texture translation offset
*/
translate : {
x: 0,
y: 0
},
/* Texture scale factors
*/
scale : {
x: .1,
y: .05
}
}
],
nodes: [
{
type: "material",
baseColor: { r: 1.0, g: 1.0, b: 1.0 },
specularColor: { r: 0.9, g: 0.9, b: 0.9 },
specular: 0.2,
shine: 6.0,
nodes: [
{
type: "geometry",
/* Indices for first three faces
*/
indices : [
/* Front
*/
0, 1, 2,
0, 2, 3,
/* Right
*/
4, 5, 6,
4, 6, 7,
/* Top
*/
8, 9,10,
8,10,11
]
}
]
}
]
},
{
type: "texture",
/* A texture can have multiple layers, each applying an
* image to a different material reflection component.
* This layer applies the Zod image to the diffuse
* component, with animated scaling.
*/
layers: [
{
uri:"../web/images/general-zod.jpg",
minFilter: "linear",
magFilter: "linear",
wrapS: "repeat",
wrapT: "repeat",
isDepth: false,
depthMode:"luminance",
depthCompareMode: "compareRToTexture",
depthCompareFunc: "lequal",
flipY: false,
width: 1,
height: 1,
internalFormat:"lequal",
sourceFormat:"alpha",
sourceType: "unsignedByte",
applyTo:"baseColor",
blendMode: "multiply",
/* Texture rotation angle in degrees
*/
rotate: 0.0,
/* Texture translation offset
*/
translate : {
x: 0,
y: 0
},
/* Texture scale factors
*/
scale : {
x: 1.0,
y: 1.0
}
}
],
nodes: [
{
type: "material",
baseColor: { r: 1.0, g: 1.0, b: 1.0 },
specularColor: { r: 0.9, g: 0.9, b: 0.9 },
specular: 0.2,
shine: 6.0,
nodes: [
{
type: "geometry",
/* Indices for remaining three faces
*/
indices : [
/* Left
*/
12,13,14,
12,14,15,
/* Bottom
*/
16,17,18,
16,18,19,
/* Back
*/
20,21,22,
20,22,23
]
}
]
}
]
}
]
}
]
}
]
}
]
}
]
}
]
});
var yaw = 30;
var pitch = -30;
var lastX;
var lastY;
var dragging = false;
var canvas = document.getElementById("theCanvas");
function mouseDown(event) {
lastX = event.clientX;
lastY = event.clientY;
dragging = true;
}
function touchStart(event) {
lastX = event.targetTouches[0].clientX;
lastY = event.targetTouches[0].clientY;
dragging = true;
}
function mouseUp() {
dragging = false;
}
function touchEnd() {
dragging = false;
}
var scene = SceneJS.scene("theScene");
function mouseMove(event) {
var posX = event.clientX;
var posY = event.clientY;
actionMove(posX,posY);
}
function touchMove(event) {
var posX = event.targetTouches[0].clientX;
var posY = event.targetTouches[0].clientY;
actionMove(posX,posY);
}
/* On a mouse/touch drag, we'll re-render the scene, passing in
* incremented angles in each time.
*/
function actionMove(posX, posY) {
if (dragging) {
yaw += (posX - lastX) * 0.5;
pitch += (posY - lastY) * -0.5;
lastX = posX;
lastY = posY;
scene.findNode("yaw").set({angle: yaw});
scene.findNode("pitch").set({angle: pitch});
}
}
canvas.addEventListener('mousedown', mouseDown, true);
canvas.addEventListener('mousemove', mouseMove, true);
canvas.addEventListener('mouseup', mouseUp, true);
canvas.addEventListener('touchstart', touchStart, true);
canvas.addEventListener('touchmove', touchMove, true);
canvas.addEventListener('touchend', touchEnd, true);
scene.start();
(C) Æliens
04/09/2009
You may not copy or print any of this material without explicit permission of the author or the publisher.
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