osg::Uniform类在GLSL中干嘛用的?

oirrm

!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

fenma3422

传递glsl中的uniform的值

oirrm

fenma3422 发表于 2014-8-20 17:34
传递glsl中的uniform的值

osg::StateSet* ss->addUniform( new osg::Uniform("LightPosition", osg::Vec3(1.0f, 0.0f, 1.0f)) );//这参数字符串"LightPosition"怎么用呀???

fenma3422

在shader开始处声明
uniform vec3 LightPosition;
接下来就可以用了

oirrm

fenma3422 发表于 2014-8-22 09:29
在shader开始处声明
uniform vec3 LightPosition;
接下来就可以用了

LightPosition 是规定好的变量名吗???
osgshader的例子里LightPosition就出现一次呀ss->addUniform( new osg::Uniform("LightPosition", osg::Vec3(1.0f, 0.0f, 1.0f)) );在字符串程序里没这个名字呀

fenma3422

自己命名，确保一致。shader里可以用也可以不用，这个看shader的实现

oirrm

fenma3422 发表于 2014-8-22 17:00
自己命名，确保一致。shader里可以用也可以不用，这个看shader的实现

下面GLSL的例子
ss->addUniform( new osg::Uniform("LightPosition", osg::Vec3(1.0f, 0.0f, 1.0f)) );
ss->addUniform( new osg::Uniform("Scale", 1.0f) );
ss->addUniform( new osg::Uniform("sampler3d", TEXUNIT_NOISE));
这三个变量名在着色器在哪使用的？

1. // August20_t.cpp : 定义控制台应用程序的入口点。
   
2. //
   
3. #include "stdafx.h"
   
4. #include <math.h>
   
5. #include <stdlib.h>
   
6. #include <osg/Notify>
   
7. #include <osgGA/GUIEventAdapter>
   
8. #include <osgGA/GUIActionAdapter>
   
9. #include <osgDB/ReadFile>
   
10. #include <osgUtil/Optimizer>
    
11. #include <osgViewer/Viewer>
    
12. #include <osg/ShapeDrawable>
    
13. #include <osg/PositionAttitudeTransform>
    
14. #include <osg/Geode>
    
15. #include <osg/Node>
    
16. #include <osg/Material>
    
17. #include <osg/Notify>
    
18. #include <osg/Vec3>
    
19. #include <osg/Texture3D>
    
20. #include <osgDB/FileUtils>
    
21. #include <osg/Program>
    
22. #include <osg/Shader>
    
23. #include <osg/Uniform>
    
24. #include <iostream>
    
25. 
    
26. #define MAXB 0x100
    
27. #define N 0x1000
    
28. #define NP 12   /* 2^N */
    
29. #define NM 0xfff
    
30. int start = 1;
    
31. int B = 5;
    
32. int BM = 5;
    
33. 
    
34. #define s_curve(t) ( t * t * (3. - 2. * t) )
    
35. #define lerp(t, a, b) ( a + t * (b - a) )
    
36. #define setup(i,b0,b1,r0,r1)\
    
37.         t = vec[i] + N;\
    
38.         b0 = ((int)t) & BM;\
    
39.         b1 = (b0+1) & BM;\
    
40.         r0 = t - (int)t;\
    
41.         r1 = r0 - 1.;
    
42. #define at3(rx,ry,rz) ( rx * q[0] + ry * q[1] + rz * q[2] )
    
43. 
    
44. static int p[MAXB + MAXB + 2];
    
45. static double g3[MAXB + MAXB + 2][3];
    
46. 
    
47. void normalize3(double v[3])
    
48. {
    
49.         double s;
    
50.         s = sqrt(v[0] * v[0] + v[1] * v[1] + v[2] * v[2]);
    
51.         v[0] = v[0] / s;
    
52.         v[1] = v[1] / s;
    
53.         v[2] = v[2] / s;
    
54. }
    
55. 
    
56. void initNoise(void)
    
57. {
    
58.         int i, j, k;
    
59.         srand(30757);
    
60.         for (i = 0 ; i < B ; i++)
    
61.         {
    
62.                 p[i] = i;
    
63.                 for (j = 0 ; j < 3 ; j++)
    
64.                         g3[i][j] = (double)((rand() % (B + B)) - B) / B;
    
65.                 normalize3(g3[i]);
    
66.         }
    
67.         while (--i) {
    
68.                 k = p[i];
    
69.                 p[i] = p[j = rand() % B];
    
70.                 p[j] = k;
    
71.         }
    
72.         for (i = 0 ; i < B + 2 ; i++) {
    
73.                 p[B + i] = p[i];
    
74.                 for (j = 0 ; j < 3 ; j++)
    
75.                         g3[B + i][j] = g3[i][j];
    
76.         }
    
77.         for (i = 0 ; i < MAXB ; i++) {
    
78.                 printf("%d ",p[i]);
    
79.                 if((i+1)%10 == 0)
    
80.                         printf("\n");
    
81.         }
    
82. }
    
83. 
    
84. 
    
85. double noise3(double vec[3])
    
86. {
    
87.         int bx0, bx1, by0, by1, bz0, bz1, b00, b10, b01, b11;
    
88.         double rx0, rx1, ry0, ry1, rz0, rz1, *q, sy, sz, a, b, c, d, t, u, v;
    
89.         int i, j;
    
90. 
    
91.         if (start) {
    
92.                 start = 0;
    
93.                 initNoise();
    
94.         }
    
95. 
    
96.         setup(0, bx0,bx1, rx0,rx1);
    
97.         setup(1, by0,by1, ry0,ry1);
    
98.         setup(2, bz0,bz1, rz0,rz1);
    
99. 
    
100.         i = p[ bx0 ];
     
101.         j = p[ bx1 ];
     
102. 
     
103.         b00 = p[ i + by0 ];
     
104.         b10 = p[ j + by0 ];
     
105.         b01 = p[ i + by1 ];
     
106.         b11 = p[ j + by1 ];
     
107. 
     
108.         t  = s_curve(rx0);
     
109.         sy = s_curve(ry0);
     
110.         sz = s_curve(rz0);
     
111. 
     
112.         q = g3[ b00 + bz0 ] ; u = at3(rx0,ry0,rz0);
     
113.         q = g3[ b10 + bz0 ] ; v = at3(rx1,ry0,rz0);
     
114.         a = lerp(t, u, v);
     
115. 
     
116.         q = g3[ b01 + bz0 ] ; u = at3(rx0,ry1,rz0);
     
117.         q = g3[ b11 + bz0 ] ; v = at3(rx1,ry1,rz0);
     
118.         b = lerp(t, u, v);
     
119. 
     
120.         c = lerp(sy, a, b);
     
121. 
     
122.         q = g3[ b00 + bz1 ] ; u = at3(rx0,ry0,rz1);
     
123.         q = g3[ b10 + bz1 ] ; v = at3(rx1,ry0,rz1);
     
124.         a = lerp(t, u, v);
     
125. 
     
126.         q = g3[ b01 + bz1 ] ; u = at3(rx0,ry1,rz1);
     
127.         q = g3[ b11 + bz1 ] ; v = at3(rx1,ry1,rz1);
     
128.         b = lerp(t, u, v);
     
129. 
     
130.         d = lerp(sy, a, b);
     
131. 
     
132.         return lerp(sz, c, d);
     
133. }
     
134. 
     
135. static osg::Image*
     
136. make3DNoiseImage(int texSize)
     
137. {
     
138.         osg::Image* image = new osg::Image;
     
139.         image->setImage(texSize, texSize, texSize,
     
140.                 4, GL_RGBA, GL_UNSIGNED_BYTE,
     
141.                 new unsigned char[4 * texSize * texSize * texSize],
     
142.                 osg::Image::USE_NEW_DELETE);
     
143. 
     
144.         const int startFrequency = 4;
     
145.         const int numOctaves = 4;
     
146. 
     
147.         int f, i, j, k, inc;
     
148.         double ni[3];
     
149.         double inci, incj, inck;
     
150.         int frequency = startFrequency;
     
151.         GLubyte *ptr;
     
152.         double amp = 0.5;
     
153. 
     
154.         osg::notify(osg::INFO) << "creating 3D noise texture... ";
     
155. 
     
156.         for (f = 0, inc = 0; f < numOctaves; ++f, frequency *= 2, ++inc, amp *= 0.5)
     
157.         {
     
158.                 //SetNoiseFrequency(frequency);
     
159.                 ptr = image->data();
     
160.                 ni[0] = ni[1] = ni[2] = 0;
     
161. 
     
162.                 inci = 1.0 / (texSize / frequency);
     
163.                 for (i = 0; i < texSize; ++i, ni[0] += inci)
     
164.                 {
     
165.                         incj = 1.0 / (texSize / frequency);
     
166.                         for (j = 0; j < texSize; ++j, ni[1] += incj)
     
167.                         {
     
168.                                 inck = 1.0 / (texSize / frequency);
     
169.                                 for (k = 0; k < texSize; ++k, ni[2] += inck, ptr += 4)
     
170.                                 {
     
171.                                         *(ptr+inc) = (GLubyte) (((noise3(ni) + 1.0) ) * 128.0);
     
172.                                 }
     
173.                         }
     
174.                 }
     
175.         }
     
176. 
     
177.         osg::notify(osg::INFO) << "DONE" << std::endl;
     
178.         return image;        
     
179. }
     
180. 
     
181. static osg::Texture3D*
     
182. make3DNoiseTexture(int texSize )
     
183. {
     
184.         osg::Texture3D* noiseTexture = new osg::Texture3D;
     
185.         noiseTexture->setFilter(osg::Texture3D::MIN_FILTER, osg::Texture3D::LINEAR);
     
186.         noiseTexture->setFilter(osg::Texture3D::MAG_FILTER, osg::Texture3D::LINEAR);
     
187.         noiseTexture->setWrap(osg::Texture3D::WRAP_S, osg::Texture3D::REPEAT);
     
188.         noiseTexture->setWrap(osg::Texture3D::WRAP_T, osg::Texture3D::REPEAT);
     
189.         noiseTexture->setWrap(osg::Texture3D::WRAP_R, osg::Texture3D::REPEAT);
     
190.         noiseTexture->setImage( make3DNoiseImage(texSize) );
     
191.         return noiseTexture;
     
192. }
     
193. 
     
194. static const char *microshaderVertSource = {
     
195.         "// microshader - colors a fragment based on its position\n"
     
196.         "varying vec4 color;\n"
     
197.         "void main(void)\n"
     
198.         "{\n"
     
199.         "    color = gl_Vertex;\n"
     
200.         "    gl_Position = gl_ModelViewProjectionMatrix * gl_Vertex;\n"
     
201.         "}\n"
     
202. };
     
203. 
     
204. static const char *microshaderFragSource = {
     
205.         "varying vec4 color;\n"
     
206.         "void main(void)\n"
     
207.         "{\n"
     
208.         "    gl_FragColor = clamp( color, 0.0, 1.0 );\n"
     
209.         "}\n"
     
210. };
     
211. 
     
212. static osg::ref_ptr<osg::Group> rootNode;
     
213. static osg::Geode*
     
214. CreateModel()
     
215. {
     
216.         osg::Geode* geode = new osg::Geode();
     
217.         geode->addDrawable(new osg::ShapeDrawable(new osg::Sphere(osg::Vec3(0.0f,0.0f,0.0f),1.0f)));
     
218.         return geode;
     
219. }
     
220. 
     
221. static osg::StateSet*
     
222. ModelInstance()
     
223. {
     
224.         static float zvalue = 0.0f;
     
225.         static osg::Node* masterModel = CreateModel();
     
226. 
     
227.         osg::PositionAttitudeTransform* xform = new osg::PositionAttitudeTransform();
     
228.         xform->setPosition(osg::Vec3( 0.0f, -1.0f, zvalue ));
     
229.         zvalue = zvalue + 2.2f;
     
230.         xform->addChild(masterModel);
     
231.         rootNode->addChild(xform);
     
232.         return xform->getOrCreateStateSet();
     
233. }
     
234. 
     
235. // load source from a file.
     
236. static void
     
237. LoadShaderSource( osg::Shader* shader, const std::string& fileName )
     
238. {
     
239.         std::string fqFileName = osgDB::findDataFile(fileName);
     
240.         if( fqFileName.length() != 0 )
     
241.         {
     
242.                 shader->loadShaderSourceFromFile( fqFileName.c_str() );
     
243.         }
     
244.         else
     
245.         {
     
246.                 osg::notify(osg::WARN) << "File "" << fileName << "" not found." << std::endl;
     
247.         }
     
248. }
     
249. 
     
250. 
     
251. static osg::Program* ErodedProgram;
     
252. static osg::Shader*  ErodedVertObj;
     
253. static osg::Shader*  ErodedFragObj;
     
254. 
     
255. 
     
256. #define TEXUNIT_SINE        1
     
257. #define TEXUNIT_NOISE       2
     
258. 
     
259. 
     
260. 
     
261. class GL2Scene : public osg::Referenced
     
262. {
     
263. public:
     
264.         GL2Scene()
     
265.         {
     
266.                 _rootNode = buildScene();
     
267.         }
     
268. 
     
269.         osg::ref_ptr<osg::Group> getRootNode() { return _rootNode; }
     
270.         void reloadShaderSource()
     
271.         {
     
272.                 LoadShaderSource( ErodedVertObj, "shaders/eroded.vert" );
     
273.                 LoadShaderSource( ErodedFragObj, "shaders/eroded.frag" );
     
274.         }
     
275. 
     
276. protected:
     
277.         ~GL2Scene(){};
     
278. 
     
279. private:        /*methods*/
     
280.         osg::ref_ptr<osg::Group> buildScene()
     
281.         {
     
282.                 osg::Texture3D* noiseTexture = make3DNoiseTexture( 32 /*128*/ );
     
283.                 rootNode = new osg::Group;
     
284.                 osg::StateSet* ss = ModelInstance();
     
285.                 ss->setTextureAttribute(TEXUNIT_NOISE, noiseTexture);
     
286.                 ErodedProgram = new osg::Program;
     
287.                 ErodedProgram->setName( "eroded" );
     
288.                 _programList.push_back( ErodedProgram );
     
289.                 ErodedVertObj = new osg::Shader( osg::Shader::VERTEX );
     
290.                 ErodedFragObj = new osg::Shader( osg::Shader::FRAGMENT );
     
291.                 ErodedProgram->addShader( ErodedFragObj );
     
292.                 ErodedProgram->addShader( ErodedVertObj );
     
293.                 ss->setAttributeAndModes(ErodedProgram, osg::StateAttribute::ON);
     
294.                 ss->addUniform( new osg::Uniform("LightPosition", osg::Vec3(1.0f, 0.0f, 1.0f)) );
     
295.                 ss->addUniform( new osg::Uniform("Scale", 1.0f) );
     
296.                 ss->addUniform( new osg::Uniform("sampler3d", TEXUNIT_NOISE));
     
297.                 reloadShaderSource();
     
298.                 return rootNode;
     
299.         }
     
300. private:        /*data*/
     
301.         osg::ref_ptr<osg::Group> _rootNode;
     
302.         std::vector< osg::ref_ptr<osg::Program> > _programList;
     
303. };
     
304. 
     
305. typedef osg::ref_ptr<GL2Scene> GL2ScenePtr;
     
306. 
     
307. 
     
308. 
     
309. int _tmain(int argc, _TCHAR* argv[])
     
310. {       
     
311.         osgViewer::Viewer viewer;
     
312.         GL2ScenePtr gl2Scene = new GL2Scene;
     
313. 
     
314.         osg::ref_ptr<osg::GraphicsContext::Traits> traits = new osg::GraphicsContext::Traits;
     
315.         traits->x = 40;
     
316.         traits->y = 40;
     
317.         traits->width = 600;
     
318.         traits->height = 480;
     
319.         traits->windowDecoration = true;
     
320.         traits->doubleBuffer = true;
     
321.         traits->sharedContext = 0;
     
322. 
     
323.         osg::ref_ptr<osg::GraphicsContext> gc = osg::GraphicsContext::createGraphicsContext(traits.get());
     
324. 
     
325.         osg::ref_ptr<osg::Camera> camera = new osg::Camera;
     
326.         camera->setGraphicsContext(gc.get());
     
327.         camera->setViewport(new osg::Viewport(0,0, traits->width, traits->height));
     
328.         GLenum buffer = traits->doubleBuffer ? GL_BACK : GL_FRONT;
     
329.         camera->setDrawBuffer(buffer);
     
330.         camera->setReadBuffer(buffer);
     
331. 
     
332.         // add this slave camera to the viewer, with a shift left of the projection matrix
     
333.         viewer.addSlave(camera.get());
     
334.        
     
335.         viewer.setSceneData(gl2Scene->getRootNode().get());
     
336.         //viewer->
     
337.         return viewer.run();
     
338.         return 0;
     
339. }
     

复制代码

fenma3422

没用到

oirrm

fenma3422 发表于 2014-8-25 16:24
没用到

ss->addUniform( new osg::Uniform("LightPosition", osg::Vec3(1.0f, 0.0f, 1.0f)) );
ss->addUniform( new osg::Uniform("Scale", 1.0f) );
ss->addUniform( new osg::Uniform("sampler3d", TEXUNIT_NOISE));
没用到？？？？上面代码复制下来就能跑呀。去掉上面三句话就出不来效果啦呀

fenma3422

确实没看到有用到的地方，除非还有别的文件？

oirrm

fenma3422 发表于 2014-8-30 13:40
确实没看到有用到的地方，除非还有别的文件？

我也纳闷呢 哥们复制下我的代码，加上库。跑下试试吧。去掉真没效果了。。。

oirrm

fenma3422 发表于 2014-8-30 13:40
确实没看到有用到的地方，除非还有别的文件？

LoadShaderSource( BlockyVertObj, "shaders/blocky.vert" );
LoadShaderSource( BlockyFragObj, "shaders/blocky.frag" );

LoadShaderSource( ErodedVertObj, "shaders/eroded.vert" );
LoadShaderSource( ErodedFragObj, "shaders/eroded.frag" );

LoadShaderSource( MarbleVertObj, "shaders/marble.vert" );
LoadShaderSource( MarbleFragObj, "shaders/marble.frag" );
我知道在哪里用的了，几个shaders文件是 加载的写好的文件呀


我以后是程序里写的那俩个呢


怪不得找不到

fenma3422

我也只看了代码里的那两

oirrm

fenma3422 发表于 2014-9-2 14:14
我也只看了代码里的那两

新手真容易被坑。。。

oirrm

fenma3422 发表于 2014-9-2 14:14
我也只看了代码里的那两

哥们，我在地球模型上挖个坑咋整呀?