[SOLVED] setting transparency (alpha) for spherescenenode?

[pandoragami]

Code: Select all

Meshbuffer->Material.DiffuseColor.setAlpha( (s32)(value * 255) );
Meshbuffer->Material.MaterialType = video::EMT_TRANSPARENT_VERTEX_ALPHA;

Sorry for my ignorance but how do I turn my sphere of IMeshSceneNode into a Meshbuffer?

[CuteAlien]

IMesh (which you got from getMes()) has functions to access the meshbuffers. That node will only have one so you just need to access the first one.

[pandoragami]

IMesh (which you got from getMes()) has functions to access the meshbuffers. That node will only have one so you just need to access the first one.

I think I have it right but still no transparency

Code: Select all

 
#include <irrlicht.h>
using namespace irr;
 
class MyEventReceiver : public IEventReceiver
{
public:
 
    struct SMouseState
    {
        core::position2di Position;
        bool LeftButtonDown;
        SMouseState() : LeftButtonDown(false) { }
    } MouseState;
 
    virtual bool OnEvent(const SEvent& event)
    {
        if (event.EventType == irr::EET_KEY_INPUT_EVENT)
            KeyIsDown[event.KeyInput.Key] = event.KeyInput.PressedDown;
 
        if(event.EventType == EET_MOUSE_INPUT_EVENT)
        {
            switch(event.MouseInput.Event)
            {
            case EMIE_LMOUSE_PRESSED_DOWN:
                MouseState.LeftButtonDown = true;
                break;
 
            case EMIE_LMOUSE_LEFT_UP:
                MouseState.LeftButtonDown = false;
                break;
 
            case EMIE_MOUSE_MOVED:
                MouseState.Position.X = event.MouseInput.X;
                MouseState.Position.Y = event.MouseInput.Y;
                break;
 
            default:
 
                break;
            }
        }
 
        return false;
    }
 
    // This is used to check whether a key is being held down
    virtual bool IsKeyDown(EKEY_CODE keyCode) const
    {
        return KeyIsDown[keyCode];
    }
 
    const SMouseState & GetMouseState(void) const
    {
        return MouseState;
    }
 
    MyEventReceiver()
    {
        for (u32 i=0; i<KEY_KEY_CODES_COUNT; ++i)
            KeyIsDown[i] = false;
    }
 
private:
    // We use this array to store the current state of each key
    bool KeyIsDown[KEY_KEY_CODES_COUNT];
};
 
MyEventReceiver receiver;
IrrlichtDevice* device = 0;
const int SCRX = 640;
const int SCRY = 480;
const float radius = 5.0f;
 
int main()
{
    device = createDevice( irr::video::EDT_OPENGL, core::dimension2d<u32>( SCRX, SCRY), 16, false, false, false, &receiver);
 
    if (device == 0)
        return 1;
 
    video::IVideoDriver* driver = device->getVideoDriver();
    scene::ISceneManager* smgr = device->getSceneManager();
 
    driver->setTextureCreationFlag(video::ETCF_CREATE_MIP_MAPS, true);
 
    scene::ICameraSceneNode* cam = smgr->addCameraSceneNodeFPS( 0, 50.0f, 0.01f, -1, 0, 0, false, 0.0f, false, true);
 
    device->getCursorControl()->setVisible(false);
    scene::IMeshSceneNode* sphere = smgr->addSphereSceneNode(radius, 32, 0, -1, core::vector3df(0, 0, 0), core::vector3df(0, 0, 0), core::vector3df(1.0f, 1.0f, 1.0f));
    sphere->setMaterialFlag(video::EMF_LIGHTING, false);
    sphere->setMaterialTexture( 0, driver->getTexture("graph.jpg"));
 
    scene::IMesh* sphere_mesh = sphere->getMesh();
    int value = 0;
    scene::IMeshBuffer* sphere_mesh_buffer = sphere_mesh->getMeshBuffer(0);
 
    sphere_mesh_buffer->getMaterial().DiffuseColor.setAlpha( (s32)(value * 255) );
    sphere_mesh_buffer->getMaterial().MaterialType = video::EMT_TRANSPARENT_ALPHA_CHANNEL;
 
    cam->setPosition( core::vector3df( 0, 0,-15));
    cam->setTarget( core::vector3df( 0.0f, 0.0f, 0.0f));
 
    int lastFPS = -1;
 
    while(device->run())
    if (device->isWindowActive())
    {
        driver->beginScene(true, true, video::SColor( 255, 0, 0, 0));
        smgr->drawAll();
        driver->endScene();
 
        int fps = driver->getFPS();
 
        if (lastFPS != fps)
        {
            core::stringw str = L"Irrlicht Text Node [";
            str += driver->getName();
            str += "] FPS:";
            str += fps;
 
            device->setWindowCaption(str.c_str());
            lastFPS = fps;
        }
 
        device->sleep(50);
    }
 
    device->drop();
 
    return 0;
}
 
 
 
 

[CuteAlien]

Oh come on - try a little bit before asking each step. Try using 0 again for example instead of 255.

[pandoragami]

Oh come on - try a little bit before asking each step. Try using 0 again for example instead of 255.

I tried 0 or 255 but no luck. Am I missing some other mesh material methods?

Code: Select all

 
scene::IMesh* sphere_mesh = sphere->getMesh();
    scene::IMeshBuffer* sphere_mesh_buffer = sphere_mesh->getMeshBuffer(0);
    sphere_mesh_buffer->getMaterial().DiffuseColor.setAlpha( 0 );
    sphere_mesh_buffer->getMaterial().MaterialType = video::EMT_TRANSPARENT_ALPHA_CHANNEL; 
 

[mongoose7]

You may need a texture.

[pandoragami]

You may need a texture.

thanks,

Besides this line?

Code: Select all

sphere->setMaterialTexture( 0, driver->getTexture("graph.jpg"));

The image does show on the sphere no problem. Is there something else I need to add for the texture? Is there transparency alpha for the texture itself?

[pandoragami]

Here's the complete code

Code: Select all

 
#include <irrlicht.h>
 
using namespace irr;
 
class MyEventReceiver : public IEventReceiver
{
public:
 
    struct SMouseState
    {
        core::position2di Position;
        bool LeftButtonDown;
        SMouseState() : LeftButtonDown(false) { }
    } MouseState;
 
    virtual bool OnEvent(const SEvent& event)
    {
        if (event.EventType == irr::EET_KEY_INPUT_EVENT)
            KeyIsDown[event.KeyInput.Key] = event.KeyInput.PressedDown;
 
        if(event.EventType == EET_MOUSE_INPUT_EVENT)
        {
            switch(event.MouseInput.Event)
            {
            case EMIE_LMOUSE_PRESSED_DOWN:
                MouseState.LeftButtonDown = true;
                break;
 
            case EMIE_LMOUSE_LEFT_UP:
                MouseState.LeftButtonDown = false;
                break;
 
            case EMIE_MOUSE_MOVED:
                MouseState.Position.X = event.MouseInput.X;
                MouseState.Position.Y = event.MouseInput.Y;
                break;
 
            default:
 
                break;
            }
        }
 
        return false;
    }
 
    // This is used to check whether a key is being held down
    virtual bool IsKeyDown(EKEY_CODE keyCode) const
    {
        return KeyIsDown[keyCode];
    }
 
    const SMouseState & GetMouseState(void) const
    {
        return MouseState;
    }
 
    MyEventReceiver()
    {
        for (u32 i=0; i<KEY_KEY_CODES_COUNT; ++i)
            KeyIsDown[i] = false;
    }
 
private:
    // We use this array to store the current state of each key
    bool KeyIsDown[KEY_KEY_CODES_COUNT];
};
 
MyEventReceiver receiver;
IrrlichtDevice* device = 0;
const int SCRX = 640;
const int SCRY = 480;
const float radius = 5.0f;
 
int main()
{
    device = createDevice( irr::video::EDT_OPENGL, core::dimension2d<u32>( SCRX, SCRY), 16, false, false, false, &receiver);
 
    if (device == 0)
        return 1;
 
    video::IVideoDriver* driver = device->getVideoDriver();
    scene::ISceneManager* smgr = device->getSceneManager();
 
    driver->setTextureCreationFlag(video::ETCF_CREATE_MIP_MAPS, true);
 
    scene::ICameraSceneNode* cam = smgr->addCameraSceneNodeFPS( 0, 50.0f, 0.01f, -1, 0, 0, false, 0.0f, false, true);
 
    device->getCursorControl()->setVisible(false);
    scene::IMeshSceneNode* sphere = smgr->addSphereSceneNode(radius, 32, 0, -1, core::vector3df(0, 0, 0), core::vector3df(0, 0, 0), core::vector3df(1.0f, 1.0f, 1.0f));
    sphere->setMaterialFlag(video::EMF_LIGHTING, false);
    sphere->setMaterialTexture( 0, driver->getTexture("graph.jpg"));
 
    scene::IMesh* sphere_mesh = sphere->getMesh();
 
    scene::IMeshBuffer* sphere_mesh_buffer = sphere_mesh->getMeshBuffer(0);
 
    sphere_mesh_buffer->getMaterial().DiffuseColor.setAlpha( 0 );
    sphere_mesh_buffer->getMaterial().MaterialType = video::EMT_TRANSPARENT_ALPHA_CHANNEL;
 
    cam->setPosition( core::vector3df( 0, 0,-15));
    cam->setTarget( core::vector3df( 0.0f, 0.0f, 0.0f));
 
    int lastFPS = -1;
 
    while(device->run())
    if (device->isWindowActive())
    {
        driver->beginScene(true, true, video::SColor( 255, 0, 0, 0));
        smgr->drawAll();
        driver->endScene();
 
        int fps = driver->getFPS();
 
        if (lastFPS != fps)
        {
            core::stringw str = L"Irrlicht Text Node [";
            str += driver->getName();
            str += "] FPS:";
            str += fps;
 
            device->setWindowCaption(str.c_str());
            lastFPS = fps;
        }
 
        device->sleep(50);
    }
 
    device->drop();
 
    return 0;
}
 
 
 
 

[CuteAlien]

Play around with the code. Did you try other material types with transparency? There is even an example (22) where you can try texture/light/material combinations. What's the point if other people are doing that for you ...
Please don't ask for every step - try figuring stuff out on your own. And only if you haven't found the solution after a day or so ask for help. It's the best way to become a better programmer - getting results just told will not help you at all in the long run.

[pandoragami]

Play around with the code. Did you try other material types with transparency? There is even an example (22) where you can try texture/light/material combinations. What's the point if other people are doing that for you ...
Please don't ask for every step - try figuring stuff out on your own. And only if you haven't found the solution after a day or so ask for help. It's the best way to become a better programmer - getting results just told will not help you at all in the long run.

Are you sure this isn't a bug though, everything makes sense in the code but it doesn't work. I don't want to waste time looking around for something if it won't work that's all, thanks for the help so far though.

[CuteAlien]

I don't know materials behavior myself without trying out stuff and looking at the results. Well, doing it often enough I get maybe faster to the results by now. But I got a transparent node in the materialviewer by playing around for less than 2 minutes just changing the alpha value and materials a few times. If you consider such basic experiments a waste of your time, that's up to you. I have never found another way of really learning a tool besides trying stuff with it myself. Good luck.

[mongoose7]

I did say TRANSPARENT_VERTEX_ALPHA! Why did you use TRANSPARENT_ALPHA_CHANNEL? Do you want it easy or hard? I tried to give you the easy way - one level of alpha across the texture. But you want it hard - one texture for the diffuse and one for the transparency. Well, now you will have to work.

[pandoragami]

Well, no problem, I wasn't able to fix it but I did get the transparency to work for a mesh without a texture, I'll just have to settle for that. I tried this page too

http://irrlicht.sourceforge.net/forum/v ... php?t=2679

but no luck using the second post
arena->setMaterialType(video::EMT_TRANSPARENT_ADD_COLOR);

[CuteAlien]

I'd like to mention that I never said to use DiffuseColor alpha. But I suppose a programmer who really tries to find a solution would have tried also what happens when using getMeshManipulator()->setVertexColorAlpha() with the other material-type like I proposed. Kinda like it's done in the example which I mention now for the 3rd time and where you can try material-settings without coding a line.

But just give up - fine by me. Textures are just ruining the pure 3D style anyway!

[pandoragami]

But I suppose a programmer who really tries to find a solution would have tried also what happens when using getMeshManipulator()->setVertexColorAlpha() with the other material-type like I proposed.

Alright well, these were the ones I did try

Code: Select all

 
sphere->setMaterialType(video::EMT_TRANSPARENT_ALPHA_CHANNEL);
sphere->setMaterialType(video::EMT_TRANSPARENT_ADD_COLOR);
sphere->setMaterialType(video::EMT_TRANSPARENT_VERTEX_ALPHA);
sphere->setMaterialType(video::EMT_TRANSPARENT_ALPHA_CHANNEL_REF);
sphere->setMaterialType(video::EMT_TRANSPARENT_REFLECTION_2_LAYER);

and only the first one works for a mesh; are there other transparent material types or would I get other results mixing video::EMT_TRANSPARENT_ALPHA_CHANNEL with other "video::EMT...." types?