(C++) Simple Diamond object/node

[Panther]

Here's a simple CDiamond class that you can paste into your code. It's nice because you don't have to physically load this object. I also provide an example of how to make it look nice below.

Code: Select all

class CDiamond : public scene::ISceneNode
{
	core::aabbox3d<f32> Box;
	video::S3DVertex Vertices[13];
	video::SMaterial Material;

public:

	CDiamond(scene::ISceneNode* parent, scene::ISceneManager* mgr, s32 id)
		: scene::ISceneNode(parent, mgr, id)
	{
		Material.Wireframe = false;
		Material.Lighting = false;

		Vertices[0] =  video::S3DVertex(-8,3,0, 0,1,0, video::SColor(192,192,192,192), 0, 1);
		Vertices[1] =  video::S3DVertex(-5,3,8, 0,1,0, video::SColor(192,192,192,192), 1, 0);
		Vertices[2] =  video::S3DVertex(-5,3,-8, 0,1,0, video::SColor(192,192,192,192), 1, 1);
		Vertices[3] =  video::S3DVertex(8,3,0, 0,1,0, video::SColor(192,192,192,192), 0, 0);
		Vertices[4] =  video::S3DVertex(5,3,8, 0,1,0, video::SColor(192,192,192,192), 0, 1);
		Vertices[5] =  video::S3DVertex(5,3,-8, 0,1,0, video::SColor(192,192,192,192), 1, 1);
		Vertices[6] =  video::S3DVertex(-11,0,0, -1,1,0, video::SColor(192,192,192,192), 1, 0);
		Vertices[7] =  video::S3DVertex(-8,0,11, -1,1,1, video::SColor(192,192,192,192), 0, 0);
		Vertices[8] =  video::S3DVertex(-8,0,-11, -1,1,-1, video::SColor(192,192,192,192), 0, 1);
		Vertices[9] =  video::S3DVertex(11,0,0, 1,1,0, video::SColor(192,192,192,192), 1, 0);
		Vertices[10] = video::S3DVertex(8,0,11, 1,1,1, video::SColor(192,192,192,192), 1, 1);
		Vertices[11] = video::S3DVertex(8,0,-11, 1,1,-1, video::SColor(192,192,192,192), 0, 0);
		Vertices[12] = video::S3DVertex(0,-15,0,0,-1,0, video::SColor(192,192,192,192), 0, 1);

	// The Irrlicht Engine needs to know the bounding box of your scene node. 
		Box.reset(Vertices[0].Pos);
		for (s32 i=1; i<13; ++i)
			Box.addInternalPoint(Vertices[i].Pos);
	}

	// Before it is drawn, the OnPreRender() method of every scene node in the scene 
	//is called by the scene manager.
	virtual void OnPreRender()
	{
		if (IsVisible)
			SceneManager->registerNodeForRendering(this);

		ISceneNode::OnPreRender();
	}

	//	In the render() method most of the interesting stuff happens: The
	// Scene node renders itself. We override this method and draw the diamond.
	virtual void render()
	{
		//If the face isn't showing up, it may be "inside out".  In other words,
		//the vector is reversed.  To fix this, swap the 1st and 3rd terms; for
		//example, if your index is 3,9,7 then change it to 7,9,3 (a,b,c becomes c,b,a).
		u16 indices[] =  //These are the faces of the diamond
		{	2,0,1,
			5,2,1,
			5,1,4,
			5,4,3,
			1,0,6, 
			0,2,8, 
			8,6,0, 
			11,8,2, 
			2,5,11, 
			11,5,3, 
			3,9,11, 
			9,3,4, 
			4,10,9, 
			10,4,1, 
			1,7,10, 
			6,7,1, 
			8,11,12,
			12,11,9,
			12,9,10,
			12,10,7,
			12,7,6, 
			6,8,12
		};
		video::IVideoDriver* driver = SceneManager->getVideoDriver();
		driver->setMaterial(Material);
		driver->setTransform(video::ETS_WORLD, AbsoluteTransformation);
		driver->drawIndexedTriangleList(&Vertices[0], 13, &indices[0], 22);
	}

	/*
	At least, we create three small additional methods.
	GetBoundingBox() returns the bounding box of this scene node, 
	GetMaterialCount() returns the amount of materials in this scene node
	(our tetraeder only has one material), and getMaterial() returns the
	material at an index. Because we have only one material here, we can
	return the only one meterial, assuming that no one ever calls getMaterial()
	with an index greater than 0.
	*/
	virtual const core::aabbox3d<f32>& getBoundingBox() const
	{
		return Box;
	}

	virtual s32 getMaterialCount()
	{
		return 1;
	}

	virtual video::SMaterial& getMaterial(s32 i)
	{
		return Material;
	}	
};

Below is an example of how I recommend displaying it - translucent, with a crystal-like finish:

Code: Select all

   diamond = new CDiamond(smgr->getRootSceneNode(), smgr, 123);
   diamond[i]->setMaterialTexture(0, driver->getTexture("crystal.jpg"));
   diamond[i]->setMaterialType(EMT_TRANSPARENT_ADD_COLOR);

Here's a screen-shot:



If you want my crystal.jpg texture, you can get it here:



In my game, I slowly rotate it, so you can see all the faces. If anyone knows how to make it shimmer or glow nicely, please let me know.

Enjoy!

[JPulham]

Set its material to have high Specular, and also you could add lens affects if you REALLY wanted, but that would be a bit OTT

Good BTW

[Joe_Oliveri]

Very cool code Nice post.

[Electron]

Looks nice, but. . .

1) Why create the indices in the render function? Create them once and store them.

2)Why not just create it as a model in a modeling package? Does it really need its own scene node type?