Posted on April 1, 2015

This project involved dealing with caustics and using refractive materials to make jewels. To shade this scene, most of the materials used were mental ray materials.
The gold shader was the first thing I worked on. I tried using a blinn material with ramps and noise because it was going to be used for a lot of objects and hence increasing the render time. Although the blinn worked well but I could not get the right specular highlight for it to look realistic. So, I started with the copper preset for the mia_material_x shader and tweaked the colors a bit. This worked really well. I used the same shader for the coins but added a blinn with a bump map (shown below) to get a better highlight and a bump. For the silver, I used the same mia_material_x shader but with the chrome preset and tweaked the settings to get a nice smooth silver shade.

 

All the gems in the scene use the mental ray dielectric_material. This worked really well especially for the diamonds. I tried using the same for the lamp glass but it was clear for that. I also tried the thick and thin glass presets but all those were giving a weird liquid like effect to the lamp. Eventually I used a glass image mapped on to it with transparency. I also gave it the refractive index of glass to make it look realistic.
The pearls and the topaz are simple maya shaders to save up on rendering time and also because they did not need any complicated shading.
The velvet on the crown and the table use a shader downloaded from the web.