Flat shading with addShadowVolumeSceneNode()

[Andreas]

Hi all,

i once more have a question i hope you guys can help me with.

Please have a look at the following Screenshots of a simple AnimatedMeshSceneNode in a scene with one light source:



After adding an IShadowVolumeSceneNode the SceneNode looks like this:



Please note the hard transition from bright to dark parts of the SceneNode. Additionally, the shadow doesn't seem to be correct (it should be a UV Sphere, but looks more like an
Icosphere in Blender terms) The system is Windows 7 with mingw and OpenGL, i exported the mesh from Blender 2.6 with Gandalfs B3D exporter (exporting normals enabled).

Here is the code i used to create the scene:

Code: Select all

 
    camera = sceneManager->addCameraSceneNode(0, vector3df(30, 20, 0), vector3df(0, 10, -10), 0);
 
    sceneManager->setAmbientLight(SColor(200, 120, 120, 120));
    sceneManager->addLightSceneNode(0, vector3df(0, 20, -10), SColor(0, 120, 120, 120), 40, 0);
 
    scene::IAnimatedMesh* mesh = sceneManager->getMesh("models/sphere.b3d");
    IAnimatedMeshSceneNode *node = 0;
 
    if (mesh) {
        node = sceneManager->addAnimatedMeshSceneNode(mesh);
        node->setScale(vector3df(4, 4, 4));
        node->setPosition(vector3df(0, 10, 0));
        node->setMaterialFlag(EMF_LIGHTING, true);
        node->setMaterialFlag(video::EMF_NORMALIZE_NORMALS, true);
        // This line is the only difference between the two screenshots.
        node->addShadowVolumeSceneNode();
    }
 

Is there any way to avoid the flat shaded parts and get a more smooth transition from the bright to the dark parts of the SceneNode?

Thanks
Andreas

[Mel]

There isn't much that can be really done. That is how the shadow volumes are calculated.

[Andreas]

Hi Mel,

thanks for the response. I had hoped there were some flags to disable shadows on the node that is causing the shadow,
but ok, i guess i'll have to live without dynamic shadows then...

Best regards
Andreas

[sudi]

You can always use shaders.
There are alot of extensions on this forum that allow dynamic soft shadows

[Andreas]

Yes you are right, i will search for a shader.
But since i don't know anything about shader programming or integrating them in irrlicht this could get a bit hard.