This sample provides easily reusable code for drawing basic geometric primitives:

• Cube
• Sphere
• Cylinder
• Torus
• Teapot

These classes are particularly useful when debugging 3D games. For example, you could use them to display your collision bounding boxes or bounding spheres as translucent or wireframe 3D models.

Minimum Shader Profile

Sample Controls

This sample provides the following geometric primitive classes:

• CubePrimitive
• SpherePrimitive
• CylinderPrimitive
• TorusPrimitive
• TeapotPrimitive

To reuse the code in a game of your own, just copy the .cs file for whichever primitive types you want to use, along with the GeometricPrimitive base class and VertexPositionNormal helper class. If you are using the TeapotPrimitive, you will also need to copy the BezierPrimitive base class.

To create a primitive model, add this code to your LoadContent method:

    teapot = new TeapotPrimitive(GraphicsDevice);

All the primitive classes have two constructor overloads. The basic version (shown above) constructs a primitive with sensible default options, and a size of one unit across. The second constructor overload has more parameters, letting you specify the size of the object and (for everything except the cube) how many triangles to tessellate it into. This lets you pick your own balance between many triangles (which will create a nice smooth looking object but may be expensive to draw) or fewer triangles (which will be more efficient but not look as good).

If you are going to be creating and destroying many different primitives as your game progresses, you should also call the Dispose method to clean up the primitive model when you have finished using it.

To display a primitive model, the Draw method has two overloads. The basic version is shown here:

    teapot.Draw(world, view, projection, color);

The basic overload draws the primitive using a BasicEffect shader with default lighting, tinted to whatever color you specify. This method sets all the important renderstates before it draws, making sure the depth buffer is enabled, culling is set to the right direction, and so on, so it works robustly even if you aren't sure what other renderstates might be set at the time. If you specify a color with a fractional alpha value, this enables alpha blending, but if your color has solid alpha, blending is disabled.

The other Draw overload takes a custom effect, so you can replace the BasicEffect shader with whatever other rendering or lighting techniques you prefer. Unlike the first version, this overload does not set any renderstates before drawing, so you must take care to set all the states you need yourself, or to define these states as part of your custom effect.