This tutorial deals with creating a simple cut gem starting from a sphere. This is a simple gem and does not try to emulate any standard cut, but it is quick and works quite well.
The Scene
We’ll start with a new project using the Dark Studio Template. Don’t forget to remove the Backdrop!
Replace the lightdome and reflected environment with the Lightdome – Physics Lab environment. Set the lightdome to an intensity of 10%
The Gem.
Create a sphere.
Drag the Complexity slider in the Object palette all the way to the left. Now we have an octahedron.
From here...
...to here
An octahedron
For the sake of comfort, it is a good idea to rotate the gem before converting to a Polygon mesh.
- Rotate 45º on the y-axis (world)
- Group the sphere
- Convert to Polygon mesh. Make sure the One-sided result checkbox is checked.
Now it is time to edit the mesh.
Select the top and bottom points of the mesh
Drag using the Bevel Element Tool
Select the four points in the middle, and drag using the Bevel Element tool
Select the four horizontal edges in the middle, and drag using the Bevel Element tool
It is very important to make sure the gem is a One Sided object and to set the Auto Smooth value to 0º from the preset 60º.
The gem is done.
The Texture
The texture is a transparent, glossy texture with the following settings:
A base gem texture
It is very important to use Fresnel interpolation in the Reflectivity channel.
Feel free to experiment using different colors and refractions.
Light and camera
Use a single spotlight, and a camera set to your liking.
Make sure all the directional lights in the Lights tab of the Environment window are set to Construction.
Camera and spotlight in place
Render
A good place to start is the PT Caustics Fine preset in the Photons menu of the render menu.
Fiddle with the settings until you are satisfied. An important point is using 4 reflectivity bounces at least.
Please share images of what you obtain 🙂
