shadow problem

Guest · Post by **Guest** » Fri Jul 09, 2004 7:54 am

Hi I am pretty new in designing effects with irrlicht. I have some problems with shadow even I looked at the tutorial about effects where niko shows the dynamic shadow and light.

So I tried it my self with a simple mesh and no dynamic shadow--- and it won't work.

Here are some basic questions:

1. it didn't make any differences wether I created a ILightSceneNode or not? do I have do create a lightscenenode in order to get shadows? if yes do I have to do anything with the lightscenenode besides creating it?

2.Do I have to do anything else than this:
marker->addShadowVolumeSceneNode();
smgr->setShadowColor(irr::video::SColor(220,0,0,0));
to create a shadow? Where do I have to set the position of the shadow if I don't need the light?

3. Do I need that world created in the tutorial around the mesh? Or should I see the shadow even on the pure background color or on an image?

4. If I have done anything right, why won't I see the shadow?

Thanks in advance

Guest · Post by **Guest** » Fri Jul 09, 2004 12:37 pm

Please could someone help?

Evil Mr Sock · Post by **Evil Mr Sock** » Fri Jul 09, 2004 7:10 pm

Yes, you need to create a light - and then, to see the shadow, you're going to have to have whatever's casting the shadow somewhere inbetween the light and some sort of surface for the shadow to be drawn on.

Guest · Post by **Guest** » Mon Jul 12, 2004 7:49 am

Thank you Evil Mr Sock!!
But still some questions. What do you mean with "whatever's casting the shadow"? You mean any mesh with that?

And the surface should be what? I can't be just a bmp or jpg where the shadow is drawn on but it has to be other meshes?

thesmileman · Post by **thesmileman** » Mon Jul 12, 2004 5:49 pm

What do you mean with "whatever's casting the shadow"?

What his whole post means is that you have to have one object, take the ground for instance, and another object, say a person, and a light. These objects must be in a row such as light, then a person, then the ground, just as the same if you step outside.

Now all you need to cast a shadow is import a mesh of the ground (This could really be anything you wanted) then another mesh of a person(This also could be anything you wanted) and then create a light or dynamic light. As long the scene would cast a shadow in real life(This does not mean reflected light and such) then it will cast a scene in Irrlicht if you have it set up to do so. Also you should use directx instead of opengl as I do not believe that shadows work as well in opengl yet as they do in directx.

Guest · Post by **Guest** » Tue Jul 13, 2004 9:34 am

Ok I did that, but it is not working.

Code: Select all

int main(){
irr::IrrlichtDevice *device = irr::createDevice(irr::video::EDT_DIRECTX9, irr::core::dimension2d<irr::s32>(512, 384), 16, false, false, 0);
	irr::video::IVideoDriver* driver = device->getVideoDriver();
	irr::scene::ISceneManager* smgr = device->getSceneManager();

	irr::scene::ICameraSceneNode* camera = smgr->addCameraSceneNode(0,irr::core::vector3df(0.0f, 0.0f, -10.0f),irr::core::vector3df(0,0,0));


	irr::scene::IAnimatedMesh* MyMesh = device->getSceneManager()->getMesh("figure.ms3d");
    irr::scene::IAnimatedMeshSceneNode* mynode= smgr->addAnimatedMeshSceneNode(MyMesh,0,-1,irr::core::vector3df(1,2,0),irr::core::vector3df(0.0f,0.0f,0.0f),irr::core::vector3df(0.05f,0.05f,0.05f));
	mynode->setMaterialTexture(0, driver->getTexture("cloth.JPG"));
	mynode->setMaterialFlag(irr::video::EMF_LIGHTING, false);


//GROUND
irr::scene::IAnimatedMesh* MyUnderMesh = device->getSceneManager()->getMesh("cube.3ds");
    irr::scene::IAnimatedMeshSceneNode* underground = smgr->addAnimatedMeshSceneNode(MyUnderMesh,0,-1,irr::core::vector3df(1,-2,0),irr::core::vector3df(-35.0f,0.0f,0.0f),irr::core::vector3df(0.5f,0.03f,0.1f));
	underground->setMaterialTexture(0, driver->getTexture("gr.jpg"));
	underground->setMaterialFlag(irr::video::EMF_LIGHTING, false);


//LIGHT
    irr::scene::ILightSceneNode* node = smgr->addLightSceneNode(0, irr::core::vector3df(1,1,1), 
        irr::video::SColorf(1.0f, 0.6f, 0.7f, 1.0f), 800.0f);

    irr::video::SLight *lm =&node->getLightData(); 
    lm->DiffuseColor = irr::video::SColorf(1.0f, 1.0f, 1.0f, 1.0f);

    mynode->addShadowVolumeSceneNode();	
    smgr->setShadowColor(irr::video::SColor(0,0,0,0));


while(device->run()) {
          driver->beginScene(true, true, irr::video::SColor(0,50,50,50));
          smgr->drawAll();
          driver->endScene();
}

device->drop();
return 0;
}

Where is the error?

thesmileman · Post by **thesmileman** » Tue Jul 13, 2004 4:51 pm

try chaning

Code: Select all

underground->setMaterialFlag(irr::video::EMF_LIGHTING, false);

to

Code: Select all

underground->setMaterialFlag(irr::video::EMF_LIGHTING, true);

Rocketeer · Post by **Rocketeer** » Tue Jul 13, 2004 10:26 pm

I'm fairly sure you also need to enable the stencil buffer for shadows... I could be wrong, but try using the line

Code: Select all

irr::IrrlichtDevice *device = irr::createDevice(irr::video::EDT_DIRECTX9, irr::core::dimension2d<irr::s32>(512, 384), 16, false, true, 0);

(Note the last-but-one parameter is now true)

See the api docs for more info:
http://irrlicht.sourceforge.net/docu/na ... .html#a177

Guest · Post by **Guest** » Wed Jul 14, 2004 7:17 am

mmmh, doesn't work...
in the api it says: Specifies if the stencil buffer should be enabled. Set this to true, if you want the engine be able to draw stencil buffer shadows. Note that not all devices are able to use the stencil buffer. If they don't no shadows will be drawn.

So which device is not able to? because it seems as mine is not...

the other suggestion made the downsite of the underground black but no shadow from the mesh on the underground is drawn on top of the cube.

thesmileman · Post by **thesmileman** » Wed Jul 14, 2004 7:31 am

Anonymous wrote:the other suggestion made the downsite of the underground black but no shadow from the mesh on the underground is drawn on top of the cube.

not entirely sure what you mean by the sentance above. but did you do this:

Code: Select all

 underground->setMaterialFlag(irr::video::EMF_LIGHTING, false);

for all of your mesh node as well or just underground? If not do it for the mesh as well.

Guest · Post by **Guest** » Wed Jul 14, 2004 7:38 am

I tried to do it with both of my meshes (the underground and the figure on the underground). the bottom of the underground turned black and some parts of the figure turned black, but there is no shadow of the figure drawn on the underground...

thesmileman · Post by **thesmileman** » Wed Jul 14, 2004 7:50 am

Ahhh I think I see the problem. It is this line of code I think:

Code: Select all

 smgr->setShadowColor(irr::video::SColor(0,0,0,0));

Correct me if I am wrong but you have set the alpha value, the first value in SColor, to 0 which would make it a completly transparent shadow!

Try something like this

Code: Select all

 smgr->setShadowColor(irr::video::SColor(180,0,0,0));

for a nice slightly transparent shadow

Guest · Post by **Guest** » Wed Jul 14, 2004 7:51 am

Ohhhhh.... it works with OpenGL!! I can see a shadow when I use OpenGL . I can't see any shadow using Direct3D. Is there any chance to get it to work with Direct3D too? because I probably have to use DirectX8 or 9 for my project.

thesmileman · Post by **thesmileman** » Wed Jul 14, 2004 7:53 am

have you tried directX 8 or just 9

Guest · Post by **Guest** » Wed Jul 14, 2004 8:20 am

I tried it with both , DirectX8 and 9. In both cases I can't see a shadow.

By the way, thanks for the hint but 0 is not transparent but solid...