Using a sphere and the Polygon Modeler, we can whip up a disco ball in no time. With a couple spotlights and caustics rendering the results are quite good.
The ball begins as a sphere.
We can adjust the number of faces we will have using the complexity slider (which is at its most complex setting). If we activate the Absolute checkbox we will get more faces.
Non-absolute complexity
Absolute complexity = more faces
We now convert the sphere into a polygon mesh.
The renderer will try to smooth the sphere out, unless we tell it not to. We do this with the Auto smooth angle. In my experience, assigning an auto smooth angle of zero usually gives better results than deactivating auto smooth.
An Auto Smooth angle of zero will make our Disco ball properly faceted.
The Disco ball is now perfectly usable. For a little extra effect, we may Normal extrude all the faces a little. This will create little spaces between the “mirrors” of our ball.
Edit the ball in the polygon modeller and select all the faces.
Outline shading is best for selecting all faces.
All faces selected
We need to extrude each face individually. To make this happen, we must make sure Region Extrude is deactivated in the Normal Extrude tool.
Make sure Region Extrude is deactivated by double-clicking on the Normal Extrude tool.
Now extrude all faces a little.
The Mirror Texture
The Mirror texture is very simple:
- No ambient
- No diffuse
- No specular
- Full reflectivity.
The Mirror texture
If we render now, there will be nothing. We need a reflected environment to be able to see the ball.
In this example, the Physics Lab environment was used, with the black point modified to make it a subtler reflected environment.
Physics Lab reflected environment
Black Point edited to make a darker reflected environment.
The render should look like this.
Disco ball
Now a 2D rectangle is added as a wall and a couple of spotlights are pointed at the ball.
Wall and spotlights
To make the spots appear on the wall, we need to use a renderer that takes photons into account. For this tutorial we used the Photons>PT Caustics Fine preset.
The render preset used to show the light spots on the wall
A Render using photons should look like this:
The ball, working properly and ready for animating.
The ball was animated with one of the Lua scripts: the Y-axis continuous rotation.
Click on the Equal sign on the right of the Rotation Property of the Disco ball.
Apply the “Y-axis continuous rotation” preset script. In this example the rotations per second are set to 0.2
Now it is time to render the animation. We should have a fully functional disco ball.
Here is the file used in the tutorial, so you can play with it or compare in case something goes funny.
