<!--
Copyright 2009, Google Inc.
All rights reserved.
Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions are
met:
* Redistributions of source code must retain the above copyright
notice, this list of conditions and the following disclaimer.
* Redistributions in binary form must reproduce the above
copyright notice, this list of conditions and the following disclaimer
in the documentation and/or other materials provided with the
distribution.
* Neither the name of Google Inc. nor the names of its
contributors may be used to endorse or promote products derived from
this software without specific prior written permission.
THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
-->
<!--
O3D Skinning example.
Shows a simple skinned cylinder.
-->
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"
"http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="content-type" content="text/html; charset=UTF-8">
<title>
Skinning.
</title>
<!-- Include sample javascript library functions-->
<script type="text/javascript" src="o3djs/base.js"></script>
<!-- Our javascript code -->
<script type="text/javascript" id="o3dscript">
o3djs.require('o3djs.util');
o3djs.require('o3djs.math');
o3djs.require('o3djs.rendergraph');
o3djs.require('o3djs.material');
o3djs.require('o3djs.primitives');
// Events
// init() once the page has finished loading.
// unload() when the page is unloaded.
window.onload = init;
window.onunload = unload;
// constants
var NUM_BONES = 11;
var BONE_SPACING = 20;
// global variables
var g_o3d;
var g_math;
var g_client;
var g_viewInfo;
var g_pack;
var g_transforms = [];
var g_finished = false; // for selenium testing.
var g_clock = 0;
var g_timeMult = 1;
/**
* Creates the client area.
*/
function init() {
o3djs.util.makeClients(initStep2);
}
/**
* Initializes O3D and creates one shape.
* @param {Array} clientElements Array of o3d object elements.
*/
function initStep2(clientElements) {
// Initializes global variables and libraries.
var o3dElement = clientElements[0];
g_o3d = o3dElement.o3d;
g_math = o3djs.math;
g_client = o3dElement.client;
// Creates a pack to manage our resources/assets
g_pack = g_client.createPack();
// Create the render graph for a view.
g_viewInfo = o3djs.rendergraph.createBasicView(
g_pack,
g_client.root,
g_client.renderGraphRoot);
// Set our projection matrix, with a vertical field of view of 45 degrees
// a near clipping plane of 0.1 and far clipping plane of 10000.
g_viewInfo.drawContext.projection = g_math.matrix4.perspective(
g_math.degToRad(45),
g_client.width / g_client.height,
0.1,
10000);
// Create a material.
var material = o3djs.material.createBasicMaterial(
g_pack,
g_viewInfo,
[1, 0.2, 1, 1]);
// Create a cylinder.
var vertexInfo = o3djs.primitives.createCylinderVertices(
40, 200, 12, 20,
[[1, 0, 0, 0],
[0, 1, 0, 0],
[0, 0, 1, 0],
[0, 100, 0, 1]]);
var shape = vertexInfo.createShape(g_pack, material);
// Create an ParamArray to hold matrices for skinning.
var matrices = g_pack.createObject('ParamArray');
// Create a Skin to hold the influences and bind pose.
var skin = g_pack.createObject('Skin');
// Create a SkinEval to use the Skin.
var skinEval = g_pack.createObject('SkinEval');
// Tell the SkinEval which matrices and Skin to use.
skinEval.matrices = matrices;
skinEval.skin = skin;
// Create matrices on our ParamArray.
matrices.resize(NUM_BONES, 'o3d.ParamMatrix4');
// Create 11 transforms for the bones and parent them into a chain.
for (var ii = 0; ii < NUM_BONES; ++ii) {
var transform = g_pack.createObject('Transform');
g_transforms[ii] = transform;
if (ii > 0) {
transform.translate(0, BONE_SPACING, 0);
}
transform.parent = ii == 0 ? g_client.root : g_transforms[ii - 1];
// Bind the world matrix of the transform to the corresponding matrix in the
// ParamArray.
matrices.getParam(ii).bind(transform.getParam('worldMatrix'));
// Store the inverse world matrix of each transform as the bind pose for the
// skin.
skin.setInverseBindPoseMatrix(ii, g_math.inverse(transform.worldMatrix));
}
// Add the cylinder to the root transform.
g_transforms[0].addShape(shape);
// Skinning happens in world space so bind the transform of the shape
// to the SkinEval so it can put our skin in object space.
skinEval.getParam('base').bind(g_transforms[0].getParam('worldMatrix'));
// Make our source data for skinning and setup the influences for each bone.
// We only need the position and normals.
var positions = [];
var normals = [];
var positionStream = vertexInfo.findStream(g_o3d.Stream.POSITION);
var normalStream = vertexInfo.findStream(g_o3d.Stream.NORMAL);
var numVertices = positionStream.numElements();
for (var ii = 0; ii < numVertices; ++ii) {
// Choose the bones to influence the vertex based on its height.
// boneArea will be a fractional value between 2 bones based on the Y
// position of the vertex. In other words, if the y Position of the vertex
// 63 and the bones are 20 units apart then boneArea will = 6.15 meaning
// it's between bones 6 and 7
var boneArea = positionStream.getElementVector(ii)[1] / BONE_SPACING;
// Pull out the fractional part of boneArea
var influence = boneArea % 1;
// Compute the bone indicies
var bone1 = Math.floor(boneArea);
var bone2 = bone1 + 1;
if (bone2 >= NUM_BONES) {
bone2 = NUM_BONES - 1;
}
// Now make each vertex be influenced by these two bones. In the example
// above where boneArea was 6.15 we let bone1 influence the vertex by
// (1 - 0.15) or 0.85 and bone2 influence it by 0.15.
skin.setVertexInfluences(ii, [bone1, 1 - influence, bone2, influence]);
}
// Create a SourceBuffer for the Skin and set the vertices on it.
var sourceBuffer = g_pack.createObject('SourceBuffer');
var positionField = sourceBuffer.createField('FloatField', 3);
var normalField = sourceBuffer.createField('FloatField', 3);
sourceBuffer.allocateElements(numVertices);
positionField.setAt(0, positionStream.elements);
normalField.setAt(0, normalStream.elements);
// Tell the skinEval how to use the SourceBuffer
skinEval.setVertexStream(g_o3d.Stream.POSITION,
0,
positionField,
0);
skinEval.setVertexStream(g_o3d.Stream.NORMAL,
0,
normalField,
0);
// Bind the Primitive's position and normal streams
// to the SkinEval so the SkinEval will fill them in each frame.
var streamBank = shape.elements[0].streamBank;
streamBank.bindStream(skinEval, g_o3d.Stream.POSITION, 0);
streamBank.bindStream(skinEval, g_o3d.Stream.NORMAL, 0);
// Setup an onrender callback for animation.
g_client.setRenderCallback(onrender);
g_finished = true; // for selenium testing.
}
/**
* Called every frame.
* @param {!o3d.RenderEvent} renderEvent Info for rendering.
*/
function onrender(renderEvent) {
// Get the number of seconds since the last render.
var elapsedTime = renderEvent.elapsedTime;
g_clock += elapsedTime * g_timeMult;
var x = Math.sin(g_clock * 0.3) * 400;
var z = Math.cos(g_clock * 0.3) * 400;
var y = Math.sin(g_clock * 0.7) * 50 + 100;
// spin the camera.
g_viewInfo.drawContext.view = g_math.matrix4.lookAt(
[x, y, z], // eye
[0, 100, 0], // target
[0, 1, 0]); // up
// Make our bone chain bend.
var rotation = Math.PI / g_transforms.length * Math.sin(g_clock * 1);
for (var ii = 1; ii < g_transforms.length; ++ii) {
var transform = g_transforms[ii];
transform.identity();
transform.translate(0, BONE_SPACING, 0);
transform.rotateX(rotation);
}
}
/**
* Removes any callbacks so they don't get called after the page has unloaded.
*/
function unload() {
if (g_client) {
g_client.cleanup();
}
}
</script>
</head>
<body>
<h1>Skinning</h1>
<!-- Start of O3D plugin -->
<div id="o3d" style="width: 800px; height: 600px;"></div>
<!-- End of O3D plugin -->
</body>
</html>