-
-
- To start, we take the program from tutorial 2, which loaded and displayed
- a quake 3 level. We will use the level to walk in it and to pick triangles
- from it. In addition we'll place 3 animated models into it for scene
- node picking. The following code starts up the engine and loads a
- quake 3 level. I will not explain it, because it should already be
- known from tutorial 2.
-
-
- #include <irrlicht.h>
-#include <iostream>
-using namespace irr;
-
-#pragma comment(lib, "Irrlicht.lib")
-
-int main()
-{
- // let user select driver type
-
video::E_DRIVER_TYPE driverType;
printf("Please select the driver you want for this example:\n"\
" (a) Direct3D 9.0c\n (b) Direct3D 8.1\n (c) OpenGL 1.5\n"\
" (d) Software Renderer\n (e) Apfelbaum Software Renderer\n"\
" (f) NullDevice\n (otherKey) exit\n\n");
char i;
std::cin >> i;
switch(i)
{
case 'a': driverType = video::EDT_DIRECT3D9;break;
case 'b': driverType = video::EDT_DIRECT3D8;break;
case 'c': driverType = video::EDT_OPENGL; break;
case 'd': driverType = video::EDT_SOFTWARE; break;
case 'e': driverType = video::EDT_BURNINGSVIDEO;break;
case 'f': driverType = video::EDT_NULL; break;
default: return 0;
}
- // create device
- IrrlichtDevice *device = createDevice(driverType,
- core::dimension2d<s32>(640, 480), 16, false);
- if (device == 0)
return 1; // could not create selected driver.
video::IVideoDriver* driver = device->getVideoDriver();
scene::ISceneManager* smgr = device->getSceneManager();
device->getFileSystem()->addZipFileArchive
("../../media/map-20kdm2.pk3");
-
-
- scene::IAnimatedMesh* q3levelmesh = smgr->getMesh("20kdm2.bsp");
- scene::ISceneNode* q3node = 0;
-
- if (q3levelmesh)
- q3node = smgr->addOctTreeSceneNode(q3levelmesh->getMesh(0));
-
- |
-
-
- So far so good, we've loaded the quake 3 level like in tutorial
- 2. Now, here comes something different: We create a triangle selector.
- A triangle selector is a class which can fetch the triangles from
- scene nodes for doing different things with them, for example collision
- detection. There are different triangle selectors, and all can be
- created with the ISceneManager. In this example, we create an OctTreeTriangleSelector,
- which optimizes the triangle output a little bit by reducing it like
- an octree. This is very useful for huge meshes like quake 3 levels.
- Afte we created the triangle selector, we attach it to the q3node.
- This is not necessary, but in this way, we do not need to care for
- the selector, for example dropping it after we do not need it anymore.
-
-
- scene::ITriangleSelector* selector = 0;
-
- if (q3node)
- {
- q3node->setPosition(core::vector3df(-1370,-130,-1400));
-
- selector = smgr->createOctTreeTriangleSelector(
- q3levelmesh->getMesh(0), q3node, 128);
- q3node->setTriangleSelector(selector);
- } |
-
-
- We add a first person shooter camera to the scene for being able
- to move in the quake 3 level like in tutorial 2. But this, time, we
- add a special animator to the camera: A Collision Response animator.
- This thing modifies the scene node to which it is attached to in that
- way, that it may no more move through walls and is affected by gravity.
- The only thing we have to tell the animator is how the world looks
- like, how big the scene node is, how gravity and so on. After the
- collision response animator is attached to the camera, we do not have
- to do anything more for collision detection, anything is done automaticly,
- all other collision detection code below is for picking. And please
- note another cool feature: The collsion response animator can be attached
- also to all other scene nodes, not only to cameras. And it can be
- mixed with other scene node animators. In this way, collision detection
- and response in the Irrlicht
- engine is really, really easy.
- Now we'll take a closer look on the parameters of createCollisionResponseAnimator().
- The first parameter is the TriangleSelector, which specifies how the
- world, against collision detection is done looks like. The second
- parameter is the scene node, which is the object, which is affected
- by collision detection, in our case it is the camera. The third defines
- how big the object is, it is the radius of an ellipsoid. Try it out
- and change the radius to smaller values, the camera will be able to
- move closer to walls after this. The next parameter is the direction
- and speed of gravity. You could set it to (0,0,0) to disable gravity.
- And the last value is just a translation: Without this, the ellipsoid
- with which collision detection is done would be around the camera,
- and the camera would be in the middle of the ellipsoid. But as human
- beings, we are used to have our eyes on top of the body, with which
- we collide with our world, not in the middle of it. So we place the
- scene node 50 units over the center of the ellipsoid with this parameter.
- And that's it, collision detection works now.
-
-
-
- scene::ICameraSceneNode* camera =
camera = smgr->addCameraSceneNodeFPS(0,100.0f,300.0f);
- camera->setPosition(core::vector3df(-100,50,-150));
-
- scene::ISceneNodeAnimator* anim =
smgr->createCollisionResponseAnimator(
- selector, camera, core::vector3df(30,50,30),
- core::vector3df(0,-3,0),
- core::vector3df(0,50,0));
- selector->drop();
- camera->addAnimator(anim);
- anim->drop(); |
-
-
- Because collision detection is no big deal in irrlicht, I'll describe
- how to do two different types of picking in the next section. But
- before this, I'll prepare the scene a little. I need three animated
- characters which we
- could pick later, a dynamic light for lighting them, a billboard for
- drawing where we found an intersection, and, yes, I need to get rid
- of this mouse cursor. :)
-
-
- // disable mouse cursor
-
- device->getCursorControl()->setVisible(false);
-
- // add billboard
-
- scene::IBillboardSceneNode * bill = smgr->addBillboardSceneNode();
- bill->setMaterialType(video::EMT_TRANSPARENT_ADD_COLOR );
- bill->setMaterialTexture(0, driver->getTexture(
"../../media/particle.bmp"));
- bill->setMaterialFlag(video::EMF_LIGHTING, false);
- bill->setSize(core::dimension2d<f32>(20.0f, 20.0f));
-
- // add 3 animated faeries.
-
- video::SMaterial material;
- material.Texture1 = driver->getTexture(
"../../media/faerie2.bmp");
- material.Lighting = true;
-
- scene::IAnimatedMeshSceneNode* node = 0;
- scene::IAnimatedMesh* faerie = smgr->getMesh(
"../../media/faerie.md2");
-
- if (faerie)
- {
- node = smgr->addAnimatedMeshSceneNode(faerie);
- node->setPosition(core::vector3df(-70,0,-90));
- node->setMD2Animation(scene::EMAT_RUN);
- node->getMaterial(0) = material;
-
- node = smgr->addAnimatedMeshSceneNode(faerie);
- node->setPosition(core::vector3df(-70,0,-30));
- node->setMD2Animation(scene::EMAT_SALUTE);
- node->getMaterial(0) = material;
-
- node = smgr->addAnimatedMeshSceneNode(faerie);
- node->setPosition(core::vector3df(-70,0,-60));
- node->setMD2Animation(scene::EMAT_JUMP);
- node->getMaterial(0) = material;
- }
-
- material.Texture1 = 0;
- material.Lighting = false;
-
- // Add a light
-
- smgr->addLightSceneNode(0, core::vector3df(-60,100,400),
- video::SColorf(1.0f,1.0f,1.0f,1.0f),
- 600.0f); |
-
-
- For not making it to complicated, I'm doing picking inside the drawing
- loop. We take two pointers for storing the current and the last selected
- scene node and start the loop.
-
-
-
- scene::ISceneNode* selectedSceneNode = 0;
- scene::ISceneNode* lastSelectedSceneNode = 0;
-
-
- int lastFPS = -1;
-
- while(device->run())
if (device->isWindowActive())
- {
- driver->beginScene(true, true, 0);
-
- smgr->drawAll(); |
-
-
- After we've drawn the whole scene whit smgr->drawAll(), we'll do
- the first picking: We want to know which triangle of the world we are
- looking at. In addition, we want the exact point of the quake 3 level
- we are looking at. For this, we create a 3d line starting at the position
- of the camera and going through the lookAt-target of it. Then we ask
- the collision manager if this line collides with a triangle of the world
- stored in the triangle selector. If yes, we draw the 3d triangle and
- set the position of the billboard to the intersection point.
-
-
- core::line3d<f32> line;
- line.start = camera->getPosition();
- line.end = line.start +
- (camera->getTarget() - line.start).normalize() * 1000.0f;
-
- core::vector3df intersection;
- core::triangle3df tri;
-
- if (smgr->getSceneCollisionManager()->getCollisionPoint(
- line, selector, intersection, tri))
- {
- bill->setPosition(intersection);
-
- driver->setTransform(video::ETS_WORLD, core::matrix4());
- driver->setMaterial(material);
- driver->draw3DTriangle(tri, video::SColor(0,255,0,0));
- } |
-
-
- Another type of picking supported by the Irrlicht Engine is scene
- node picking based on bouding boxes. Every scene node has got a bounding
- box, and because of that, it's very fast for example to get the scene
- node which the camera looks
- at. Again, we ask the collision manager for this, and if we've got a
- scene node, we highlight it by disabling Lighting in its material, if
- it is not the billboard or the quake 3 level.
-
-
- selectedSceneNode = smgr->getSceneCollisionManager()->
- getSceneNodeFromCameraBB(camera);
-
- if (lastSelectedSceneNode)
- lastSelectedSceneNode->setMaterialFlag(
- video::EMF_LIGHTING, true);
-
- if (selectedSceneNode == q3node ||
- selectedSceneNode == bill)
- selectedSceneNode = 0;
-
- if (selectedSceneNode)
- selectedSceneNode->setMaterialFlag(
- video::EMF_LIGHTING, false);
-
- lastSelectedSceneNode = selectedSceneNode; |
-
-
- That's it, we just have to finish drawing.
-
-
- driver->endScene();
-
- int fps = driver->getFPS();
-
- if (lastFPS != fps)
- {
- core::stringw str = L"Collision detection example - Irrlicht Engine [";
str += driver->getName();
str += "] FPS:";
str += fps;
device->setWindowCaption(str.c_str());
lastFPS = fps;
}
- }
-
- device->drop();
-
- return 0;
-}
-
- |
-
-
-
-
- |
-
-
