irrlicht/examples/11.PerPixelLighting/tutorial.html
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<title>Irrlicht Engine Tutorial</title>
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<td bgcolor="#666699" width="10"><b><a href="http://irrlicht.sourceforge.net" target="_blank"><img src="../../media/irrlichtlogo.jpg" width="88" height="31" border="0"></a></b></td>
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<div align="left"><b><font color="#FFFFFF">Tutorial 11. Per pixel lighting</font></b></div>
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<p> This tutorial shows how to use one of the built in more complex materials
in irrlicht: Per pixel lighted surfaces using normal maps and parallax
mapping. It will also show how to use fog and moving particle systems.
And don't panic: You dont need any experience with shaders to use these
materials in Irrlicht.</p>
<p>The program which is described here will look like this:</p>
<p align="center"><img src="../../media/011shot.jpg" width="258" height="202"><br>
</p>
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<td bgcolor="#666699"> <b><font color="#FFFFFF">Lets start!</font></b></td>
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<td height="90" bgcolor="#eeeeff" valign="top"> <div align="left">
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<p>At first, we need to include all headers and do the stuff we always
do, like in nearly all other tutorials.</p>
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<td> <pre>#include &lt;irrlicht.h&gt;<br>#include &lt;iostream&gt;<br><br>using namespace irr;<br><br>#pragma comment(lib, &quot;Irrlicht.lib&quot;)<br></pre></td>
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<p>For this example, we need an event receiver, to make it possible
for the user to switch between the three available material types.
In addition, the event receiver will create some small GUI window
which displays what material is currently being used. There is nothing
special done in this class, so maybe you want to skip reading it.</p>
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<td><pre>class MyEventReceiver : public IEventReceiver
{
public:
MyEventReceiver(scene::ISceneNode* room,
gui::IGUIEnvironment* env, video::IVideoDriver* driver)
{
// store pointer to room so we can change its drawing mode
Room = room;
Driver = driver;
// set a nicer font
gui::IGUISkin* skin = env->getSkin();
gui::IGUIFont* font = env->getFont("../../media/fonthaettenschweiler.bmp");
if (font)
skin->setFont(font);
// add window and listbox
gui::IGUIWindow* window = env->addWindow(
core::rect<s32>(490,390,630,470), false, L"Use 'E' + 'R' to change");
ListBox = env->addListBox(
core::rect<s32>(2,22,135,78), window);
ListBox->addItem(L"Diffuse");
ListBox->addItem(L"Bump mapping");
ListBox->addItem(L"Parallax mapping");
ListBox->setSelected(1);
// create problem text
ProblemText = env->addStaticText(
L"Your hardware or this renderer is not able to use the "\
L"needed shaders for this material. Using fall back materials.",
core::rect<s32>(150,20,470,60));
ProblemText->setOverrideColor(video::SColor(100,255,255,255));
// set start material (prefer parallax mapping if available)
video::IMaterialRenderer* renderer =
Driver->getMaterialRenderer(video::EMT_PARALLAX_MAP_SOLID);
if (renderer && renderer->getRenderCapability() == 0)
ListBox->setSelected(2);
// set the material which is selected in the listbox
setMaterial();
}
bool OnEvent(const SEvent& event)
{
// check if user presses the key 'E' or 'R'
if (event.EventType == irr::EET_KEY_INPUT_EVENT &&
!event.KeyInput.PressedDown && Room && ListBox)
{
// change selected item in listbox
int sel = ListBox->getSelected();
if (event.KeyInput.Key == irr::KEY_KEY_R)
++sel;
else
if (event.KeyInput.Key == irr::KEY_KEY_E)
--sel;
else
return false;
if (sel > 2) sel = 0;
if (sel < 0) sel = 2;
ListBox->setSelected(sel);
// set the material which is selected in the listbox
setMaterial();
}
return false;
}
private:
// sets the material of the room mesh the the one set in the
// list box.
void setMaterial()
{
video::E_MATERIAL_TYPE type = video::EMT_SOLID;
// change material setting
switch(ListBox->getSelected())
{
case 0: type = video::EMT_SOLID;
break;
case 1: type = video::EMT_NORMAL_MAP_SOLID;
break;
case 2: type = video::EMT_PARALLAX_MAP_SOLID;
break;
}
Room->setMaterialType(type);</pre>
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<p>We need to add a warning if the materials will not be able to be
displayed 100% correctly. This is no problem, they will be renderered
using fall back materials, but at least the user should know that
it would look better on better hardware. We simply check if the material
renderer is able to draw at full quality on the current hardware.
The IMaterialRenderer::getRenderCapability() returns 0 if this is
the case.<br>
</p>
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<td> <pre>video::IMaterialRenderer* renderer = Driver->getMaterialRenderer(type);
// display some problem text when problem
if (!renderer || renderer->getRenderCapability() != 0)
ProblemText->setVisible(true);
else
ProblemText->setVisible(false);
}
private:
gui::IGUIStaticText* ProblemText;
gui::IGUIListBox* ListBox;
scene::ISceneNode* Room;
video::IVideoDriver* Driver;
};</pre></td>
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<p><br>
Now for the real fun. We create an Irrlicht Device and start to setup
the scene.<br>
</p>
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<td> <pre>int main()
{
// let user select driver type
video::E_DRIVER_TYPE driverType = video::EDT_DIRECT3D9;
<br> printf(&quot;Please select the driver you want for this example:\n&quot;\<br> &quot; (a) Direct3D 9.0c\n (b) Direct3D 8.1\n (c) OpenGL 1.5\n&quot;\<br> &quot; (d) Software Renderer\n (e) Apfelbaum Software Renderer\n&quot;\<br> &quot; (f) NullDevice\n (otherKey) exit\n\n&quot;);<br>
char i;
std::cin >> i;
switch(i)<br> {<br> case 'a': driverType = video::EDT_DIRECT3D9;break;<br> case 'b': driverType = video::EDT_DIRECT3D8;break;<br> case 'c': driverType = video::EDT_OPENGL; break;<br> case 'd': driverType = video::EDT_SOFTWARE; break;<br> case 'e': driverType = video::EDT_BURNINGSVIDEO;break;<br> case 'f': driverType = video::EDT_NULL; break;<br> default: return 0;<br> }
// create device
IrrlichtDevice* device = createDevice(driverType, core::dimension2d<s32>(640, 480));
if (device == 0)
return 1; // could not create selected driver.
</pre></td>
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<br>
Before we start with the interesting stuff, we do some simple things:
Store pointers to the most important parts of the engine (video driver,<br>
scene manager, gui environment) to safe us from typing too much, add
an irrlicht engine logo to the window and a user controlled first person
shooter style camera. Also, we let the engine now that it should store
all textures in 32 bit. This necessary because for parallax mapping,
we need 32 bit textures.<br>
<br>
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<td> <pre>
video::IVideoDriver* driver = device->getVideoDriver();
scene::ISceneManager* smgr = device->getSceneManager();
gui::IGUIEnvironment* env = device->getGUIEnvironment();
driver->setTextureCreationFlag(video::ETCF_ALWAYS_32_BIT, true);
// add irrlicht logo
env->addImage(driver->getTexture("../../media/irrlichtlogoalpha.tga"),
core::position2d<s32>(10,10));
// add camera
scene::ICameraSceneNode* camera =
smgr->addCameraSceneNodeFPS(0,100.0f,300.0f);
camera->setPosition(core::vector3df(-200,200,-200));
// disable mouse cursor
device->getCursorControl()->setVisible(false);</pre></td>
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<br>
Because we want the whole scene to look a little bit scarier, we add
some fog to it. This is done by a call to IVideoDriver::setFog(). There
you can set<br>
various fog settings. In this example, we use pixel fog, because it
will work well with the materials we'll use in this example. Please
note that you will have to set the material flag EMF_FOG_ENABLE to 'true'
in every scene node which should be affected by this fog.<br>
<br>
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<td> <pre>driver-&gt;setFog(video::SColor(0,138,125,81), true, 250, 1000, 0, true);<br></pre></td>
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<br>
To be able to display something interesting, we load a mesh from a .3ds
file which is a room I modeled with anim8or. It is the same room as
<br>
from the specialFX example. Maybe you remember from that tutorial, I
am no good modeler at all and so I totally messed up the texture mapping
in this model, but we can simply repair it with the IMeshManipulator::makePlanarTextureMapping()
method.<br>
<br>
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<td> <pre> scene::IAnimatedMesh* roomMesh = smgr->getMesh(
"../../media/room.3ds");
scene::ISceneNode* room = 0;
if (roomMesh)
{
smgr->getMeshManipulator()->makePlanarTextureMapping(
roomMesh->getMesh(0), 0.003f);</pre></td>
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<br>
Now for the first exciting thing: If we successfully loaded the mesh
we need to apply textures to it. Because we want this room to be displayed
with a very cool material, we have to do a little bit more than just
set the textures. Instead of only loading a color map as usual, we also
load a height map which is simply a grayscale texture. From this height
map, we create a normal map which we will set as second texture of the
room. If you already have a normal map, you could directly set it, but
I simply didn&acute;t find a nice normal map for this texture. The normal
map texture is being generated by the makeNormalMapTexture method<br>
of the VideoDriver. The second parameter specifies the height of the
heightmap. If you set it to a bigger value, the map will look more rocky.<br>
<br>
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<td> <pre> video::ITexture* colorMap = driver->getTexture("../../media/rockwall.bmp");
video::ITexture* normalMap = driver->getTexture("../../media/rockwall_height.bmp");
driver->makeNormalMapTexture(normalMap, 9.0f);</pre></td>
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<br>
But just setting color and normal map is not everything. The material
we want to use needs some additional informations per vertex like tangents
and binormals.<br>
Because we are too lazy to calculate that information now, we let Irrlicht
do this for us. That's why we call IMeshManipulator::createMeshWithTangents().
It<br>
creates a mesh copy with tangents and binormals from any other mesh.
After we've done that, we simply create a standard mesh scene node with
this<br>
mesh copy, set color and normal map and adjust some other material settings.
Note that we set EMF_FOG_ENABLE to true to enable fog in the room.<br>
<br>
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<td> <pre>scene::IMesh* tangentMesh = smgr-&gt;getMeshManipulator()-&gt;createMeshWithTangents(<br> roomMesh-&gt;getMesh(0));<br> <br> room = smgr-&gt;addMeshSceneNode(tangentMesh);<br> room-&gt;setMaterialTexture(0, colorMap);<br> room-&gt;setMaterialTexture(1, normalMap);<br> room-&gt;getMaterial(0).SpecularColor.set(0,0,0,0);<br> room-&gt;setMaterialFlag(video::EMF_FOG_ENABLE, true);<br> room-&gt;setMaterialType(video::EMT_PARALLAX_MAP_SOLID); <br> room-&gt;getMaterial(0).MaterialTypeParam = 0.02f; // adjust height for parallax effect<br> // drop mesh because we created it with a create.. call.<br> tangentMesh-&gt;drop();<br> }<br></pre></td>
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<br>
After we've created a room shaded by per pixel lighting, we add a sphere
into it with the same material, but we'll make it transparent. In addition,<br>
because the sphere looks somehow like a familiar planet, we make it
rotate. The procedure is similar as before. The difference is that we
are loading <br>
the mesh from an .x file which already contains a color map so we do
not need to load it manually. But the sphere is a little bit too small
for our needs, so we scale it by the factor 50.<br>
<br>
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<td> <pre>// add earth sphere
scene::IAnimatedMesh* earthMesh = smgr->getMesh("../../media/earth.x");
if (earthMesh)
{
// create mesh copy with tangent informations from original earth.x mesh
scene::IMesh* tangentSphereMesh =
smgr->getMeshManipulator()->createMeshWithTangents(earthMesh->getMesh(0));
// set the alpha value of all vertices to 200
smgr->getMeshManipulator()->setVertexColorAlpha(tangentSphereMesh, 200);
// scale the mesh by factor 50
smgr->getMeshManipulator()->scaleMesh(
tangentSphereMesh, core::vector3df(50,50,50));
// create mesh scene node
scene::ISceneNode* sphere = smgr->addMeshSceneNode(tangentSphereMesh);
sphere->setPosition(core::vector3df(-70,130,45));
// load heightmap, create normal map from it and set it
video::ITexture* earthNormalMap = driver->getTexture("../../media/earthbump.bmp");
driver->makeNormalMapTexture(earthNormalMap, 20.0f);
sphere->setMaterialTexture(1, earthNormalMap);
// adjust material settings
sphere->setMaterialFlag(video::EMF_FOG_ENABLE, true);
sphere->setMaterialType(video::EMT_NORMAL_MAP_TRANSPARENT_VERTEX_ALPHA);
// add rotation animator
scene::ISceneNodeAnimator* anim =
smgr->createRotationAnimator(core::vector3df(0,0.1f,0));
sphere->addAnimator(anim);
anim->drop();
// drop mesh because we created it with a create.. call.
tangentSphereMesh->drop();
}</pre></td>
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<br>
Per pixel lighted materials only look cool when there are moving lights.
So we add some. And because moving lights alone are so boring, we add
billboards <br>
to them, and a whole particle system to one of them. We start with the
first light which is red and has only the billboard attached.<br>
<br>
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<td> <pre>// add light 1 (nearly red)
scene::ILightSceneNode* light1 =
smgr->addLightSceneNode(0, core::vector3df(0,0,0),
video::SColorf(0.5f, 1.0f, 0.5f, 0.0f), 200.0f);
// add fly circle animator to light 1
scene::ISceneNodeAnimator* anim =
smgr->createFlyCircleAnimator (core::vector3df(50,300,0),190.0f, -0.003f);
light1->addAnimator(anim);
anim->drop();
// attach billboard to the light
scene::ISceneNode* bill =
smgr->addBillboardSceneNode(light1, core::dimension2d<f32>(60, 60));
bill->setMaterialFlag(video::EMF_LIGHTING, false);
bill->setMaterialType(video::EMT_TRANSPARENT_ADD_COLOR);
bill->setMaterialTexture(0, driver->getTexture("../../media/particlered.bmp"));</pre></td>
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<br>
Now the same again, with the second light. The difference is that we
add a particle system to it too. And because the light moves, the particles
of the particlesystem will follow. If you want to know more about how
particle systems are created in Irrlicht, take a look at the specialFx
example.<br>
Maybe you will have noticed that we only add 2 lights, this has a simple
reason: The low end version of this material was written in ps1.1 and
vs1.1, which doesn't allow more lights. You could add a third light
to the scene, but it won't be used to shade the walls. But of course,
this will change in future versions of Irrlicht were higher versions
of pixel/vertex shaders will be implemented too.<br>
<br>
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<td> <pre>// add light 2 (gray)
scene::ISceneNode* light2 =
smgr->addLightSceneNode(0, core::vector3df(0,0,0),
video::SColorf(1.0f, 0.2f, 0.2f, 0.0f), 200.0f);
// add fly circle animator to light 2
anim = smgr->createFlyCircleAnimator (core::vector3df(0,150,0),200.0f);
light2->addAnimator(anim);
anim->drop();
// attach billboard to light
bill = smgr->addBillboardSceneNode(light2, core::dimension2d<f32>(120, 120));
bill->setMaterialFlag(video::EMF_LIGHTING, false);
bill->setMaterialType(video::EMT_TRANSPARENT_ADD_COLOR);
bill->setMaterialTexture(0, driver->getTexture("../../media/particlewhite.bmp"));
// add particle system
scene::IParticleSystemSceneNode* ps =
smgr->addParticleSystemSceneNode(false, light2);
ps->setParticleSize(core::dimension2d<f32>(30.0f, 40.0f));
// create and set emitter
scene::IParticleEmitter* em = ps->createBoxEmitter(
core::aabbox3d<f32>(-3,0,-3,3,1,3),
core::vector3df(0.0f,0.03f,0.0f),
80,100,
video::SColor(0,255,255,255), video::SColor(0,255,255,255),
400,1100);
ps->setEmitter(em);
em->drop();
// create and set affector
scene::IParticleAffector* paf = ps->createFadeOutParticleAffector();
ps->addAffector(paf);
paf->drop();
// adjust some material settings
ps->setMaterialFlag(video::EMF_LIGHTING, false);
ps->setMaterialTexture(0, driver->getTexture("../../media/fireball.bmp"));
ps->setMaterialType(video::EMT_TRANSPARENT_VERTEX_ALPHA);
MyEventReceiver receiver(room, env, driver);
device->setEventReceiver(&receiver);</pre></td>
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<br>
Finally, draw everything. That's it.<br>
<br>
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<td> <pre>int lastFPS = -1;
while(device->run())
if (device->isWindowActive())
{
driver->beginScene(true, true, 0);
smgr->drawAll();
env->drawAll();
driver->endScene();
int fps = driver->getFPS();
if (lastFPS != fps)
{
core::stringw str = L"Per pixel lighting example - Irrlicht Engine [";
str += driver->getName();
str += "] FPS:";
str += fps;
device->setWindowCaption(str.c_str());
lastFPS = fps;
}
}
device->drop();
return 0;
}
</pre></td>
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<br>
</div>
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<p>&nbsp;</p>
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