In this tutorial, we will cover how to use the Standard Surface shader to create realistic materials such as glass and metal. We will also replace the existing scene's lighting with the Skydome light in combination with a Physical Sky shader to give us more control and a more realistic look. Lastly, we will add a background and render the scene.
The original Maya scene files for this series of tutorials can be downloaded from Autodesk's Hyperspace Madness production.
This tutorial will cover the following topics:
Our intergalactic hero 'Sven', whom we will be shading, lighting and rendering with MtoA
The lighting looks a little bit dark. Try increasing the Exposure of the Ai Skydome light to around 1 (f-stop).
When you are happy with the lighting and are ready for final rendering, increase the number of Samples to 3 in the Ai Skydome light to reduce any shadow noise. Otherwise, keep it at 1 when test rendering with the IPR.
The scene contains various Blinn and Phong shaders. We want to convert these shaders to more physically accurate shaders within MtoA. Fortunately, we can use the shader Type menu in the Attribute Editor window to convert them. We will largely be using the multi-purpose Standard Surface shader.
Sven's space suit comprises of several Blinn shaders assigned to his arms, legs, and torso.
Select one of the shaders and change the shader 'Type' from Blinn to Standard Surface. Maya will automatically connect the file texture to the Base Color, which is what we want.
More information about Specular Fresnel can be found here.
To get a realistic skin shading effect, we will use the Standard Surface shader again. It has a realistic Sub-Surface Scattering attribute which suits our single color map well.
For the hair, we will create a simple plastic looking shader.
The eye geometry consists of two objects in this scene: Eyes and Corneas. The eye geometry sits inside the cornea geometry. Therefore the eye color should be assigned to the eyeball.
Cornea geometry surrounding Eye geometry
Opaque disabled for the Cornea geometry (left). Final Cornea shader (right).
Your finished eyeball render should look like the image below.
We will assign a glass material to the helmet. The helmet has been modeled with thickness, and the normals are facing in the right direction. This is essential when rendering realistic glass surfaces with MtoA.
More information about rendering glass surfaces can be found here.
Increase the Transmission Weight to 1 so that the glass is fully transparent. Change the IOR (Index of Refraction) to that of glass (1.5). If you want to add a tint color to the glass, change the Transmission Color to a light color.
The Transmission Ray Depth is set to 8 by default. If we lower this value and render the helmet glass we can see that the eye cornea (also a refractive material) appears black. This is because the ray depth is limited and therefore cannot penetrate the glass and the cornea shader.
Let's change the shaders on Sven's collar (and air tank) to have a more 'metallic' appearance.
Open up Sampling in the Render Settings Window. For test rendering Camera (AA) samples at 3 is fine. However, for final frame rendering, you will want to increase it to at least 5.
A simple guide to sampling can be found here.
When rendering scenes with MtoA it is a good idea to get familiar with the Arnold Log in the Diagnostics tab of the Render Settings window. This log file will show you any warnings and statistics which will help you diagnose your scene file.
A guide on how to read a render log can be found here.
That's it. Congratulations, you have completed this tutorial. Now go out there and explore new worlds of rendering!