Tutorial - Stereo rendering - Revision history

Marciano at 16:45, 3 January 2010

2010-01-03T16:45:08Z

Wakko at 13:03, 13 July 2009

2009-07-13T13:03:41Z

Wakko at 11:49, 12 July 2009

2009-07-12T11:49:27Z

Wakko at 11:41, 12 July 2009

2009-07-12T11:41:40Z

Wakko at 11:41, 12 July 2009

2009-07-12T11:41:22Z

Wakko at 12:24, 11 July 2009

2009-07-11T12:24:48Z

Wakko at 11:59, 11 July 2009

2009-07-11T11:59:53Z

Wakko at 11:52, 11 July 2009

2009-07-11T11:52:50Z

Wakko at 11:42, 11 July 2009

2009-07-11T11:42:11Z

Wakko at 11:39, 11 July 2009

2009-07-11T11:39:18Z

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← Older revision		Revision as of 16:45, 3 January 2010
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		+	__NOTOC__ __NOEDITSECTION__{{ContentBlock\|color=white\|content={{!!}}
	'''In this tutorial I will describe how to perform quadbuffered stereo rendering with Horde3D. This explicitly requires a graphics card that supports quad-buffering, i.e. rendering to two different output devices(Nvidia Quadro or ATI/AMD FireGL). This has been tested with a stereo projection system and polarization glasses.'''		'''In this tutorial I will describe how to perform quadbuffered stereo rendering with Horde3D. This explicitly requires a graphics card that supports quad-buffering, i.e. rendering to two different output devices(Nvidia Quadro or ATI/AMD FireGL). This has been tested with a stereo projection system and polarization glasses.'''

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	- add a second camera node for easier camera movement		- add a second camera node for easier camera movement
		+	}}

@@ Line 6: / Line 6: @@
 [http://www.orthostereo.com/geometryopengl.html Stereoscopic Geometry in OpenGL]
-In this tutorial we will only use an asymmetric frustum.
+In this tutorial we will only use an symmetric frustum.
@@ Line 175: / Line 175: @@
 == TODO ==
-- calculate symmetric frustum
+- calculate asymmetric frustum
 - add a second camera node for easier camera movement

@@ Line 75: / Line 75: @@
 == Render the scene ==
-Now we need to calculate the eye offset and render the scene twice for both eyes. This is done by switching the Horde3D render buffer for each eye, moving the camera to the desired eye offset and render the scene to the specified buffer. Again, this will only be done if stereo rendering was enabled successfully.
+Now we need to calculate the eye offset and render the scene twice (once for each eye). This is done by switching the Horde3D render buffer to the corresponding eye, moving the camera to the desired eye offset and render the scene to the specified buffer. Again, this will only be done if stereo rendering has been enabled successfully.
 We will calculate the eye offset by simply "strafing" the camera from its original position slightly to the left and right and rotating it inwards. This example has some keys assigned to adjust the eye offset and strabismus ("cross-eyedness") on the fly. In normal (non-stereo) mode we can switch between the eyes to check the camera position even if stereo rendering is not available.

@@ Line 176: / Line 176: @@
 == TODO ==
 - calculate symmetric frustum
 - add a second camera node for easier camera movement

@@ Line 104: / Line 104: @@
 			Horde3D::setNodeTransform( _cam, _x-xEyeOffset, _y, _z-zEyeOffset, _rx ,_ry-strabismus, 0, 1, 1, 1 );
 			Horde3D::render( _cam );
 			Horde3D::setNodeParami(_cam, CameraNodeParams::OutputBufferIndex, 1);
 			Horde3D::setNodeTransform( _cam, _x+xEyeOffset, _y, _z+zEyeOffset, _rx ,_ry+strabismus, 0, 1, 1, 1 );
 			Horde3D::render( _cam );
+		}
 		else { // non stereo
@@ Line 119: / Line 117: @@
 				Horde3D::setNodeTransform( _cam, _x, _y, _z, _rx ,_ry, 0, 1, 1, 1 );
 			Horde3D::render( _cam );
+		}
 		// Remove all overlays
@@ Line 126: / Line 123: @@
 		// Write all mesages to log file
 		Horde3DUtils::dumpMessages();
 		SDL_GL_SwapBuffers();
@@ Line 174: / Line 173: @@
 </source>
 }}

@@ Line 22: / Line 22: @@
 	appWidth = fullscreen ? videoInfo->current_w : width;
 	appHeight = fullscreen ? videoInfo->current_h : height;
 	if(fullscreen)

@@ Line 37: / Line 37: @@
 			std::cerr << "STEREO initialization failed! Restarting..."<< std::endl;
 			SDL_GL_SetAttribute(SDL_GL_STEREO, 0);
-			if (!SDL_SetVideoMode(width, height, 32, SDL_OPENGL | SDL_FULLSCREEN | SDL_HWSURFACE)) {
+			if (!(surface =  SDL_SetVideoMode(appWidth, appHeight, 32, SDL_OPENGL | SDL_FULLSCREEN | SDL_HWSURFACE))) {
 			     std::cerr << "SDL_SetVideoMode failed: " << SDL_GetError() << std::endl;
 			     SDL_Quit();
@@ Line 79: / Line 79: @@
 Now we need to calculate the eye offset and render the scene twice for both eyes. This is done by switching the Horde3D render buffer for each eye, moving the camera to the desired eye offset and render the scene to the specified buffer. Again, this will only be done if stereo rendering was enabled successfully.
-We will calculate the eye offset by simply "strafing" the camera from its original position slightly to the left and right and rotating it inwards. This example has some keys assigned to adjust the eye offset and strabismus ("cross-eyedness") on the fly. In normal (non-stereo) mode we can switch between the eyes to check if the camera position even if stereo rendering is not available.
+We will calculate the eye offset by simply "strafing" the camera from its original position slightly to the left and right and rotating it inwards. This example has some keys assigned to adjust the eye offset and strabismus ("cross-eyedness") on the fly. In normal (non-stereo) mode we can switch between the eyes to check the camera position even if stereo rendering is not available.
 {{CppSourceCode|
 description= Render the scene (app.cpp)|

@@ Line 66: / Line 66: @@
 }}
-This will also work with GLFW.
+This will also work with GLFW. Just call this line before opening your GLFW window.
 {{CppSourceCode|
 description= GLFW stereo flag|

@@ Line 88: / Line 88: @@
 int eye = 0;
 void Application::mainLoop( int fps )
+{
 	_curFPS = fps;
 	keyHandler();
 	if(! _freeze )
+	{
 		// calculate eye-offsets for stereo rendering
 		float xEyeOffset = eyOffsetFactor*sinf( degToRad( _ry + 90 ) );
 		float zEyeOffset = eyOffsetFactor*cosf( degToRad( _ry + 90 ) );
 		// ........
 		// Render scene
 		// render stereo
 		int ga = 0;
 		if (SDL_GL_GetAttribute(SDL_GL_STEREO, &ga) == 0 && ga == 1) {
 			Horde3D::setNodeParami(_cam, CameraNodeParams::OutputBufferIndex, 0);
 			Horde3D::setNodeTransform( _cam, _x-xEyeOffset, _y, _z-zEyeOffset, _rx ,_ry-strabismus, 0, 1, 1, 1 );
 			Horde3D::render( _cam );
 			Horde3D::finalizeFrame();  // comment this line if you are using Horde3D 1.0.0 beta 2
 			Horde3D::setNodeParami(_cam, CameraNodeParams::OutputBufferIndex, 1);
 			Horde3D::setNodeTransform( _cam, _x+xEyeOffset, _y, _z+zEyeOffset, _rx ,_ry+strabismus, 0, 1, 1, 1 );
 			Horde3D::render( _cam );
 			Horde3D::finalizeFrame(); // comment this line if you are using Horde3D 1.0.0 beta 2
+		}
+		else { // non stereo
 			// Set camera parameters
 			if (eye == 1)  // left eye
 				Horde3D::setNodeTransform( _cam, _x-xEyeOffset, _y, _z-zEyeOffset, _rx ,_ry-strabismus, 0, 1, 1, 1 );
 			else if (eye == 2)  // right eye
 				Horde3D::setNodeTransform( _cam, _x+xEyeOffset, _y, _z+zEyeOffset, _rx ,_ry+strabismus, 0, 1, 1, 1 );
 			else if(eye == 0)  // normal camera (centered)
 				Horde3D::setNodeTransform( _cam, _x, _y, _z, _rx ,_ry, 0, 1, 1, 1 );
 			Horde3D::render( _cam );
 			Horde3D::finalizeFrame();  // comment this line if you are using Horde3D 1.0.0 beta 2
+		}
 		// Remove all overlays
 		Horde3D::clearOverlays();
 		// Write all mesages to log file
 		Horde3DUtils::dumpMessages();
 		SDL_GL_SwapBuffers();
+	}
+}
 void Application::keyPressEvent( SDLKey key )
+{
 	// add more key events here...
 	// switch between eyes (0: normal/center, 1: left eye, 2: right eye)
 	if( key == SDLK_F5 )	{// F5
 		++eye;
 		if (eye >= 3)
 			eye = 0;
 		std::cout<<"eye: "<<eye<<std::endl;
+	}
+}
 void Application::keyHandler()
+{
 	// add more keys if desired...
@@ Line 201: / Line 152: @@
 	// adjust strabismus (cross eyedness)
 	if(_keys[SDLK_0])
+	{
 		if (strabismus < 45)
 			strabismus += 0.3f;
+	}
 	if(_keys[SDLK_9])
+	{
 		if (strabismus > 0)
 			strabismus -= 0.3f;
+	}
 	// adjust eye offset
 	if(_keys[SDLK_8])
+	{
 		eyeOffset += 0.3f;
+	}
 	if(_keys[SDLK_7])
+	{
 		if (eyeOffset > 0) {
 			eyeOffset -= 0.3f;
+		}
+	}
+}