1 public function render(stage3D:Stage3D):void {
2 var i:int;
3 var j:int;
4 var light:Light3D;
5 var occluder:Occluder;
6 // Error checking
7 if (stage3D == null) throw new TypeError("Parameter stage3D must be non-null.");
8 // Reset the counters
9 numDraws = 0;
10 numTriangles = 0;
11 // Reset the occluders
12 occludersLength = 0;
13 // Reset the lights
14 lightsLength = 0;
15 ambient[0] = 0;
16 ambient[1] = 0;
17 ambient[2] = 0;
18 ambient[3] = 1;
19 // Receiving the context
20 var currentContext3D:Context3D = stage3D.context3D;
21 if (currentContext3D != context3D) {
22 if (currentContext3D != null) {
23 context3DProperties = context3DPropertiesPool[currentContext3D];
24 if (context3DProperties == null) {
25 context3DProperties = new RendererContext3DProperties();
26 context3DProperties.isConstrained = currentContext3D.driverInfo.lastIndexOf("(Baseline Constrained)") >= 0;
27 context3DPropertiesPool[currentContext3D] = context3DProperties;
28 }
29 context3D = currentContext3D;
30 } else {
31 context3D = null;
32 context3DProperties = null;
33 }
34 }
35 if (context3D != null && view != null && renderer != null && (view.stage != null || view._canvas != null)) {
36 renderer.camera = this;
37 // Projection argument calculating
38 calculateProjection(view._width, view._height);
39 // Preparing to rendering
40 view.configureContext3D(stage3D, context3D, this);
41 // Transformations calculating
42 if (transformChanged) composeTransforms();
43 localToGlobalTransform.copy(transform);
44 globalToLocalTransform.copy(inverseTransform);
45 // Searching for upper hierarchy point
46 var root:Object3D = this;
47 while (root.parent != null) {
48 root = root.parent;
49 if (root.transformChanged) root.composeTransforms();
50 localToGlobalTransform.append(root.transform);
51 globalToLocalTransform.prepend(root.inverseTransform);
52 }
53
54 // Check if object of hierarchy is visible
55 if (root.visible) {
56 // Calculating the matrix to transform from the camera space to local space
57 root.cameraToLocalTransform.combine(root.inverseTransform, localToGlobalTransform);
58 // Calculating the matrix to transform from local space to the camera space
59 root.localToCameraTransform.combine(globalToLocalTransform, root.transform);
60
61 globalMouseHandlingType = root.mouseHandlingType;
62 // Checking the culling
63 if (root.boundBox != null) {
64 calculateFrustum(root.cameraToLocalTransform);
65 root.culling = root.boundBox.checkFrustumCulling(frustum, 63);
66 } else {
67 root.culling = 63;
68 }
69 // Calculations of content visibility
70 if (root.culling >= 0) root.calculateVisibility(this);
71 // Calculations visibility of children
72 root.calculateChildrenVisibility(this);
73 // Calculations of transformations from occluder space to the camera space
74 for (i = 0; i < occludersLength; i++) {
75 occluder = occluders[i];
76 occluder.localToCameraTransform.calculateInversion(occluder.cameraToLocalTransform);
77 occluder.transformVertices(correctionX, correctionY);
78 occluder.distance = orthographic ? occluder.localToCameraTransform.l : (occluder.localToCameraTransform.d * occluder.localToCameraTransform.d + occluder.localToCameraTransform.h * occluder.localToCameraTransform.h + occluder.localToCameraTransform.l * occluder.localToCameraTransform.l);
79 occluder.enabled = true;
80 }
81 // Sorting the occluders by disance
82 if (occludersLength > 1) sortOccluders();
83 // Constructing the volumes of occluders, their intersections, starts from closest
84 for (i = 0; i < occludersLength; i++) {
85 occluder = occluders[i];
86 if (occluder.enabled) {
87 occluder.calculatePlanes(this);
88 if (occluder.planeList != null) {
89 for (j = i + 1; j < occludersLength; j++) { // It is possible, that start value should be 0
90 var compared:Occluder = occluders[j];
91 if (compared.enabled && compared != occluder && compared.checkOcclusion(occluder, correctionX, correctionY)) compared.enabled = false;
92 }
93 } else {
94 occluder.enabled = false;
95 }
96 }
97 // Reset of culling
98 occluder.culling = -1;
99 }
100 // Gather the occluders which will affects now
101 for (i = 0, j = 0; i < occludersLength; i++) {
102 occluder = occluders[i];
103 if (occluder.enabled) {
104 // Debug
105 occluder.collectDraws(this, null, 0, false);
106 if (debug && occluder.boundBox != null && (checkInDebug(occluder) & Debug.BOUNDS)) Debug.drawBoundBox(this, occluder.boundBox, occluder.localToCameraTransform);
107 occluders[j] = occluder;
108 j++;
109 }
110 }
111 occludersLength = j;
112 occluders.length = j;
113 // Check light influence
114 for (i = 0, j = 0; i < lightsLength; i++) {
115 light = lights[i];
116 light.localToCameraTransform.calculateInversion(light.cameraToLocalTransform);
117 if (light.boundBox == null || occludersLength == 0 || !light.boundBox.checkOcclusion(occluders, occludersLength, light.localToCameraTransform)) {
118 light.red = ((light.color >> 16) & 0xFF) * light.intensity / 255;
119 light.green = ((light.color >> 8) & 0xFF) * light.intensity / 255;
120 light.blue = (light.color & 0xFF) * light.intensity / 255;
121 // Debug
122 light.collectDraws(this, null, 0, false);
123 if (debug && light.boundBox != null && (checkInDebug(light) & Debug.BOUNDS)) Debug.drawBoundBox(this, light.boundBox, light.localToCameraTransform);
124
125 // Shadows preparing
126 if (light.shadow != null) {
127 light.shadow.process(this);
128 }
129 lights[j] = light;
130 j++;
131 }
132 light.culling = -1;
133 }
134 lightsLength = j;
135 lights.length = j;
136
137 // Sort lights by types
138 if (lightsLength > 0) sortLights(0, lightsLength - 1);
139
140 // Calculating the rays of mouse events
141 view.calculateRays(this, (globalMouseHandlingType & Object3D.MOUSE_HANDLING_MOVING) != 0,
142 (globalMouseHandlingType & Object3D.MOUSE_HANDLING_PRESSING) != 0,
143 (globalMouseHandlingType & Object3D.MOUSE_HANDLING_WHEEL) != 0,
144 (globalMouseHandlingType & Object3D.MOUSE_HANDLING_MIDDLE_BUTTON) != 0,
145 (globalMouseHandlingType & Object3D.MOUSE_HANDLING_RIGHT_BUTTON) != 0);
146 for (i = origins.length; i < view.raysLength; i++) {
147 origins[i] = new Vector3D();
148 directions[i] = new Vector3D();
149 }
150 raysLength = view.raysLength;
151
152 if (renderClearsContext) {
153 var r:Number = ((view.backgroundColor >> 16) & 0xff)/0xff;
154 var g:Number = ((view.backgroundColor >> 8) & 0xff)/0xff;
155 var b:Number = (view.backgroundColor & 0xff)/0xff;
156 if (view._canvas != null) {
157 r *= view.backgroundAlpha;
158 g *= view.backgroundAlpha;
159 b *= view.backgroundAlpha;
160 }
161 context3D.clear(r, g, b, view.backgroundAlpha);
162 }
163
164 // Check getting in frustum and occluding
165 if (root.culling >= 0 && (root.boundBox == null || occludersLength == 0 || !root.boundBox.checkOcclusion(occluders, occludersLength, root.localToCameraTransform))) {
166 // Check if the ray crossing the bounding box
167 if (globalMouseHandlingType > 0 && root.boundBox != null) {
168 calculateRays(root.cameraToLocalTransform);
169 root.listening = root.boundBox.checkRays(origins, directions, raysLength);
170 } else {
171 root.listening = globalMouseHandlingType > 0;
172 }
173 // Check if object needs in lightning
174 var excludedLightLength:int = root._excludedLights.length;
175 if (lightsLength > 0 && root.useLights) {
176 // Pass the lights to children and calculate appropriate transformations
177 var childLightsLength:int = 0;
178 if (root.boundBox != null) {
179 for (i = 0; i < lightsLength; i++) {
180 light = lights[i];
181 // Checking light source for existing in excludedLights
182 j = 0;
183 while (j<excludedLightLength && root._excludedLights[j]!=light) j++;
184 if (j<excludedLightLength) continue;
185
186 light.lightToObjectTransform.combine(root.cameraToLocalTransform, light.localToCameraTransform);
187 // Detect influence
188 if (light.boundBox == null || light.checkBound(root)) {
189 childLights[childLightsLength] = light;
190 childLightsLength++;
191 }
192 }
193 } else {
194 // Calculate transformation from light space to object space
195 for (i = 0; i < lightsLength; i++) {
196 light = lights[i];
197 // Checking light source for existing in excludedLights
198 j = 0;
199 while (j<excludedLightLength && root._excludedLights[j]!=light) j++;
200 if (j<excludedLightLength) continue;
201
202 light.lightToObjectTransform.combine(root.cameraToLocalTransform, light.localToCameraTransform);
203
204 childLights[childLightsLength] = light;
205 childLightsLength++;
206 }
207 }
208 root.collectDraws(this, childLights, childLightsLength, root.useShadow);
209 } else {
210 root.collectDraws(this, null, 0, root.useShadow);
211 }
212 // Debug the boundbox
213 if (debug && root.boundBox != null && (checkInDebug(root) & Debug.BOUNDS)) Debug.drawBoundBox(this, root.boundBox, root.localToCameraTransform);
214 }
215 // Gather the draws for children
216 root.collectChildrenDraws(this, lights, lightsLength, root.useShadow);
217 // Mouse events prosessing
218 view.processMouseEvents(context3D, this);
219 // Render
220 renderer.render(context3D);
221 }
222 // Output
223 if (view._canvas == null) {
224 if (renderPresentsContext) {
225 context3D.present();
226 }
227 } else {
228 context3D.drawToBitmapData(view._canvas);
229 context3D.present();
230 }
231 }
232 // Clearing
233 lights.length = 0;
234 childLights.length = 0;
235 occluders.length = 0;
236 }
看到上面的216行：root.collectChildrenDraws(this, lights, lightsLength, root.useShadow)，这句话的意思就是收集所有子节点的绘制信息。
下面详细介绍一下，是如何把各种顶点，纹理，法线信息传送到context3D的。
1 alternativa3d function collectChildrenDraws(camera:Camera3D, lights:Vector.<Light3D>, lightsLength:int, useShadow:Boolean):void {
2 var i:int;
3 var light:Light3D;
4
5 for (var child:Object3D = childrenList; child != null; child = child.next) {
6 // Checking visibility flag
7 if (child.visible) {
8 // Check getting in frustum and occluding
9 if (child.culling >= 0 && (child.boundBox == null || camera.occludersLength == 0 || !child.boundBox.checkOcclusion(camera.occluders, camera.occludersLength, child.localToCameraTransform))) {
10 // Check if the ray crossing the bounding box
11 if (child.boundBox != null) {
12 camera.calculateRays(child.cameraToLocalTransform);
13 child.listening = child.boundBox.checkRays(camera.origins, camera.directions, camera.raysLength);
14 } else {
15 child.listening = true;
16 }
17 // Check if object needs in lightning
18 var excludedLightLength:int = child._excludedLights.length;
19 if (lightsLength > 0 && child.useLights) {
20 // Pass the lights to children and calculate appropriate transformations
21 var childLightsLength:int = 0;
22 var j:int;
23 if (child.boundBox != null) {
24 for (i = 0; i < lightsLength; i++) {
25 light = lights[i];
26 // Checking object for existing in excludedLights
27 j = 0;
28 while (j<excludedLightLength && child._excludedLights[j]!=light) j++;
29 if (j<excludedLightLength) continue;
30
31 light.lightToObjectTransform.combine(child.cameraToLocalTransform, light.localToCameraTransform);
32 // Detect influence
33 if (light.boundBox == null || light.checkBound(child)) {
34 camera.childLights[childLightsLength] = light;
35 childLightsLength++;
36 }
37 }
38 } else {
39 // Calculate transformation from light space to object space
40 for (i = 0; i < lightsLength; i++) {
41 light = lights[i];
42 // Проверка источника света на отсутствие в excludedLights
43 j = 0;
44 while (j<excludedLightLength && child._excludedLights[j]!=light) j++;
45 if (j<excludedLightLength) continue;
46 light.lightToObjectTransform.combine(child.cameraToLocalTransform, light.localToCameraTransform);
47 camera.childLights[childLightsLength] = light;
48 childLightsLength++;
49 }
50 }
51 child.collectDraws(camera, camera.childLights, childLightsLength, useShadow&&child.useShadow);
52 } else {
53 child.collectDraws(camera, null, 0, useShadow&&child.useShadow);
54 }
55 // Debug the boundbox
56 if (camera.debug && child.boundBox != null && (camera.checkInDebug(child) & Debug.BOUNDS)) Debug.drawBoundBox(camera, child.boundBox, child.localToCameraTransform);
57 }
58 // Gather the draws for children
59 if (child.childrenList != null) child.collectChildrenDraws(camera, lights, lightsLength, useShadow && child.useShadow);
60 }
61 }
62 }
看上面代码的51行：child.collectDraws(camera, camera.childLights, childLightsLength, useShadow&&child.useShadow);每个Child都有一个collectDraws方法，这个方法是整个程序的关键之处。看下面代码
1 override alternativa3d function collectDraws(camera:Camera3D, lights:Vector.<Light3D>, lightsLength:int, useShadow:Boolean):void {
2 var geometry:Geometry = getGeometry(camera.context3D);
3 if (surface.material != null) surface.material.collectDraws(camera, surface, geometry, lights, lightsLength, useShadow, alwaysOnTop ? Renderer.NEXT_LAYER : -1);
4 // Mouse events.
5 if (listening) camera.view.addSurfaceToMouseEvents(surface, geometry, transformProcedure);
6 }
看第二行的GetGeometry方法，这个方法就是收集各种顶点信息的。
1 alternativa3d function getGeometry(context:Context3D):Geometry {
2 var geometry:Geometry = geometries[context];
3 if (geometry == null) {
4 geometry = new Geometry(4);
5
6 var attributes:Array = [];
7 attributes[0] = VertexAttributes.POSITION;
8 attributes[1] = VertexAttributes.POSITION;
9 attributes[2] = VertexAttributes.POSITION;
10 attributes[3] = VertexAttributes.NORMAL;
11 attributes[4] = VertexAttributes.NORMAL;
12 attributes[5] = VertexAttributes.NORMAL;
13 attributes[6] = VertexAttributes.TEXCOORDS[0];
14 attributes[7] = VertexAttributes.TEXCOORDS[0];
15 attributes[8] = VertexAttributes.TEXCOORDS[1];
16 attributes[9] = VertexAttributes.TEXCOORDS[1];
17 attributes[10] = VertexAttributes.TEXCOORDS[2];
18 attributes[11] = VertexAttributes.TEXCOORDS[2];
19 attributes[12] = VertexAttributes.TEXCOORDS[3];
20 attributes[13] = VertexAttributes.TEXCOORDS[3];
21 attributes[14] = VertexAttributes.TEXCOORDS[4];
22 attributes[15] = VertexAttributes.TEXCOORDS[4];
23 attributes[16] = VertexAttributes.TEXCOORDS[5];
24 attributes[17] = VertexAttributes.TEXCOORDS[5];
25 attributes[18] = VertexAttributes.TEXCOORDS[6];
26 attributes[19] = VertexAttributes.TEXCOORDS[6];
27 attributes[20] = VertexAttributes.TEXCOORDS[7];
28 attributes[21] = VertexAttributes.TEXCOORDS[7];
29 attributes[22] = VertexAttributes.TANGENT4;
30 attributes[23] = VertexAttributes.TANGENT4;
31 attributes[24] = VertexAttributes.TANGENT4;
32 attributes[25] = VertexAttributes.TANGENT4;
33 geometry.addVertexStream(attributes);
34
35 geometry.setAttributeValues(VertexAttributes.POSITION, Vector.<Number>([0, 0, 0, 0, 1, 0, 1, 1, 0, 1, 0, 0]));
36 geometry.setAttributeValues(VertexAttributes.NORMAL, Vector.<Number>([0, 0, -1, 0, 0, -1, 0, 0, -1, 0, 0, -1]));
37 geometry.setAttributeValues(VertexAttributes.TEXCOORDS[0], Vector.<Number>([0, 0, 0, 1, 1, 1, 1, 0]));
38 geometry.setAttributeValues(VertexAttributes.TEXCOORDS[1], Vector.<Number>([0, 0, 0, 1, 1, 1, 1, 0]));
39 geometry.setAttributeValues(VertexAttributes.TEXCOORDS[2], Vector.<Number>([0, 0, 0, 1, 1, 1, 1, 0]));
40 geometry.setAttributeValues(VertexAttributes.TEXCOORDS[3], Vector.<Number>([0, 0, 0, 1, 1, 1, 1, 0]));
41 geometry.setAttributeValues(VertexAttributes.TEXCOORDS[4], Vector.<Number>([0, 0, 0, 1, 1, 1, 1, 0]));
42 geometry.setAttributeValues(VertexAttributes.TEXCOORDS[5], Vector.<Number>([0, 0, 0, 1, 1, 1, 1, 0]));
43 geometry.setAttributeValues(VertexAttributes.TEXCOORDS[6], Vector.<Number>([0, 0, 0, 1, 1, 1, 1, 0]));
44 geometry.setAttributeValues(VertexAttributes.TEXCOORDS[7], Vector.<Number>([0, 0, 0, 1, 1, 1, 1, 0]));
45
46 geometry.indices = Vector.<uint>([0, 1, 3, 2, 3, 1]);
47
48 geometry.upload(context);
49 geometries[context] = geometry;
50 }
51 return geometry;
52 }
请看48行的代码；看到没有，对了，这个时候，顶点信息就已经上传到context3d中了。
1 override public function upload(context3D:Context3D):void {
2 var vBuffer:VertexStream;
3 var i:int;
4 var numBuffers:int = _vertexStreams.length;
5 if (_indexBuffer != null) {
6 // Clear old resources
7 _indexBuffer.dispose();
8 _indexBuffer = null;
9 for (i = 0; i < numBuffers; i++) {
10 vBuffer = _vertexStreams[i];
11 if (vBuffer.buffer != null) {
12 vBuffer.buffer.dispose();
13 vBuffer.buffer = null;
14 }
15 }
16 }
17 if (_indices.length <= 0 || _numVertices <= 0) {
18 return;
19 }
20
21 for (i = 0; i < numBuffers; i++) {
22 vBuffer = _vertexStreams[i];
23 var numMappings:int = vBuffer.attributes.length;
24 var data:ByteArray = vBuffer.data;
25 if (data == null) {
26 throw new Error("Cannot upload without vertex buffer data.");
27 }
28 vBuffer.buffer = context3D.createVertexBuffer(_numVertices, numMappings);
29 vBuffer.buffer.uploadFromByteArray(data, 0, 0, _numVertices);
30 }
31 var numIndices:int = _indices.length;
32 _indexBuffer = context3D.createIndexBuffer(numIndices);
33 _indexBuffer.uploadFromVector(_indices, 0, numIndices);
34 }
至此，这个3d引擎的Sprite3D就介绍完了。