Alpha transparency ~ help me

[ssuny1007]

you know ~ Alpha transparency ?

how can i set the Material's setting...

/// my source...




#include <irrlicht.h>
#include <iostream>

using namespace irr;

#pragma comment(lib, "Irrlicht.lib")


class CSampleSceneNode : public scene::ISceneNode
{
core::aabbox3d<f32> Box;
video::S3DVertex Vertices[6];
video::SMaterial Material;
public:
CSampleSceneNode(scene::ISceneNode* parent, scene::ISceneManager* mgr, s32 id)
: scene::ISceneNode(parent, mgr, id)
{
video::IVideoDriver* driver = SceneManager->getVideoDriver();

Material.Wireframe = false;
Material.Lighting = false;
Material.MaterialType = video::EMT_TRANSPARENT_ALPHA_CHANNEL;
//EMT_TRANSPARENT_ALPHA_CHANNEL
//EMT_TRANSPARENT_ADD_COLOR
Material.Textures[0] = driver->getTexture("Fire03.bmp");

s32 al = 255;

Vertices[0] = video::S3DVertex(-400,300,0, 1,1,0, video::SColor(al,255,255,255), 0, 0);
Vertices[1] = video::S3DVertex(400,-300,0, 1,0,0, video::SColor(al,255,255,255), 1, 1);
Vertices[2] = video::S3DVertex(-400,-300,0, 0,1,1, video::SColor(al,255,255,255), 0, 1);
Vertices[3] = video::S3DVertex(-400,300,0, 0,0,1, video::SColor(al,255,255,255), 0, 0);
Vertices[4] = video::S3DVertex(400,300,0, 0,0,1, video::SColor(al,255,255,255), 1, 0);
Vertices[5] = video::S3DVertex(400,-300,0, 0,0,1, video::SColor(al,255,255,255), 1, 1);

Box.reset(Vertices[0].Pos);
for (s32 i=1; i<6; ++i)
Box.addInternalPoint(Vertices.Pos);
}

virtual void OnRegisterSceneNode()
{
if (IsVisible)
SceneManager->registerNodeForRendering(this);

ISceneNode::OnRegisterSceneNode();
}

virtual void render()
{
u16 indices[] = {0,1,2,3,4,5};
video::IVideoDriver* driver = SceneManager->getVideoDriver();

driver->setMaterial(Material);
driver->setTransform(video::ETS_WORLD, AbsoluteTransformation);
driver->drawIndexedTriangleList(&Vertices[0], 6, &indices[0], 2);
}


virtual const core::aabbox3d<f32>& getBoundingBox() const
{
return Box;
}

virtual u32 getMaterialCount()
{
return 1;
}

virtual video::SMaterial& getMaterial(u32 i)
{
return Material;
}
};

int main()
{

video::E_DRIVER_TYPE driverType;



IrrlichtDevice *device =
createDevice(video::EDT_DIRECT3D9, core::dimension2d<s32>(800, 600), 16, false);

if (device == 0)
return 1;
device->setWindowCaption(L"Custom Scene Node - Irrlicht Engine Demo");

video::IVideoDriver* driver = device->getVideoDriver();
scene::ISceneManager* smgr = device->getSceneManager();

smgr->addCameraSceneNode(0, core::vector3df(0,0,-500), core::vector3df(0,0,0));

CSampleSceneNode *myNode =
new CSampleSceneNode(smgr->getRootSceneNode(), smgr, 666);

myNode->drop();

myNode->setScale(core::vector3df(0.5f,0.5f,0.5f));

scene::ISceneNodeAnimator* anim =
smgr->createRotationAnimator(core::vector3df(0.0f, 0.0f, 1.0f));

//myNode->addAnimator(anim);
anim->drop();

u32 frames=0;
while(device->run())
{
driver->beginScene(true, true, video::SColor(100,0,0,255));

smgr->drawAll();

driver->endScene();
if (++frames==100)
{
core::stringw str = L"Irrlicht Engine [";
str += driver->getName();
str += L"] FPS: ";
str += (s32)driver->getFPS();

device->setWindowCaption(str.c_str());
frames=0;
}
}

device->drop();

return 0;
}

[vitek]

As discussed over messenger, if you are going to attempt to use the material type video::EMT_TRANSPARENT_ALPHA_CHANNEL, you need to use a texture that has an alpha channel. The most common BITMAP formats don't support an alpha channel. The normal 24-bit format only has RGB color information. Unless you are using 32-bpp bitmaps, the result won't be like you want. The TARGA format supports an alpha channel, all you have to do is use it. As an example...

Code: Select all

  Material.MaterialType = video::EMT_TRANSPARENT_ALPHA_CHANNEL; 
  Material.Textures[0] = driver->getTexture("../../media/irrlichtlogoalpha2.tga"); 

Travis

[ssuny1007]

i Sucess ~ AlphaBlending...

but .. if i change the Alpha Value 100 .. it is not transparency..

Like this.. (Directx)


g_Device->SetTextureStageState(0,D3DTSS_COLORARG1,D3DTA_TEXTURE);
g_Device->SetTextureStageState(0,D3DTSS_COLORARG2,D3DTA_CURRENT);
g_Device->SetTextureStageState(0,D3DTSS_COLOROP,D3DTOP_MODULATE);
g_Device->SetTextureStageState(0,D3DTSS_ALPHAARG1,D3DTA_TEXTURE);
g_Device->SetTextureStageState(0,D3DTSS_ALPHAARG2,D3DTA_CURRENT);
g_Device->SetTextureStageState(0,D3DTSS_ALPHAOP,D3DTOP_SELECTARG1);

g_Device->SetRenderState(D3DRS_ALPHABLENDENABLE,TRUE);
g_Device->SetRenderState(D3DRS_SRCBLEND,D3DBLEND_SRCALPHA);
g_Device->SetRenderState(D3DRS_DESTBLEND,D3DBLEND_INVSRCALPHA);

.......

[vitek]

Please read the documentation on EMT_TRANSPARENT_ALPHA_CHANNEL in SMaterial.h. Specifically have a look at the mention of MaterialTypeParam.

Travis