History: Create Tetrahedron with MOGRE

/// <summary>
/// Create a tetrahedron with point of origin in middle of volume. 
/// It will be added to the SceneManager as ManualObject. The material must still exists.
/// </summary>
/// <param name="position">Position in scene</param>
/// <param name="scale">Size of the tetrahedron</param>
/// <param name="name">Name of the ManualObject that will be created</param>
/// <param name="materialName">Name of the used material</param>
///
void CreateTetrahedron(String name, Vector3 position, Single scale, String materialName)
{
    ManualObject manObTetra = new ManualObject(name);
    manObTetra.CastShadows = false;

    // render just before overlays (so all objects behind the transparen tetrahedron are visible)
    manObTetra.RenderQueueGroup = (byte)RenderQueueGroupID.RENDER_QUEUE_OVERLAY - 1; // = 99

    Vector3[] c = new Vector3[4]; // corners

    // calculate corners of tetrahedron (with point of origin in middle of volume)
    Single mbot = scale * 0.2f;      // distance middle to bottom
    Single mtop = scale * 0.62f;     // distance middle to top    
    Single mf   = scale * 0.289f;    // distance middle to front
    Single mb   = scale * 0.577f;    // distance middle to back
    Single mlr  = scale * 0.5f;      // distance middle to left right 
    //               width / hight / depth
    c[0] = new Vector3(-mlr, -mbot,  mf);  // left bottom front
    c[1] = new Vector3( mlr, -mbot,  mf);  // right bottom front
    c[2] = new Vector3(   0, -mbot, -mb);  // (middle) bottom back
    c[3] = new Vector3(   0,  mtop,   0);  // (middle) top (middle)

    // add position offset for all corners (move tetrahedron)
    for (Int16 i = 0;   i <= 3;   i++)
        c[i] += position;

    // create bottom
    manObTetra.Begin(materialName, RenderOperation.OperationTypes.OT_TRIANGLE_LIST);
    manObTetra.Position(c[2]);
    manObTetra.Position(c[1]);
    manObTetra.Position(c[0]);
    manObTetra.Triangle(0, 1, 2);
    manObTetra.End();
    // create right back side
    manObTetra.Begin(materialName, RenderOperation.OperationTypes.OT_TRIANGLE_LIST);
    manObTetra.Position(c[1]);
    manObTetra.Position(c[2]);
    manObTetra.Position(c[3]);
    manObTetra.Triangle(0, 1, 2);
    manObTetra.End();
    // create left back side
    manObTetra.Begin(materialName, RenderOperation.OperationTypes.OT_TRIANGLE_LIST);
    manObTetra.Position(c[3]);
    manObTetra.Position(c[2]);
    manObTetra.Position(c[0]);
    manObTetra.Triangle(0, 1, 2);
    manObTetra.End();
    // create front side
    manObTetra.Begin(materialName, RenderOperation.OperationTypes.OT_TRIANGLE_LIST);
    manObTetra.Position(c[0]);
    manObTetra.Position(c[1]);
    manObTetra.Position(c[3]);
    manObTetra.Triangle(0, 1, 2);
    manObTetra.End();

} // CreateTetrahedron

// a material with the name materialName must be created or loaded!

Vector3 position = new Vector3(1, 1, -1);
Single size = 1;
String tetraName = "terta";

// create manual object
CreateTetrahedron(tetraName, position, size, materialName);

// attach to scene
mScene.Smgr.RootSceneNode.AttachObject(mScene.Smgr.GetManualObject(tetraName));

// remove tetrahedrons
if (mScene.Smgr.HasManualObject(tetraName))
    mScene.Smgr.GetManualObject(tetraName).Clear();