# Displacement: Killamari wip

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Version 17

In this tutorial we will cover how to convert a scene that has been setup for use with the mental ray renderer to MtoA. We will cover how to shade the Killamari character character using the Ai Standard shader. We will also cover using displacement on the body object and use Arnold's subdivision to create a smooth looking mesh. Finally, we will create a simple studio lighting setup that we can use to light our character.

The original Maya scene files for this series of tutorials can be downloaded from Autodesk's Hyperspace Madness production page here.

This tutorial will cover the following topics:

Displacement: Killamari wip

Displacement: Killamari wip

Displacement

Displacement: Killamari wip

Displacement: Killamari wip

#### Subdivision

• Start off by opening the Killamari model in Maya. You will notice that it is a low poly model. We can add geometry detail by increasing the number of Subdivision Iterations using Arnold's Subdivision settings. We will also need to add subdivisions to the leg and tentacle models as we will be adding displacement to them.

#### Override Sets

Rather than having to change the number of Subdivisions for each model we can add any changes to a Maya Set and override that set.

• Select the body geometry (not the tentacles) and create a Maya Set for them.
• Select the Set and go to the Arnold tab. Click on Add to open the Add Override Attribute window.
• We want to create a smooth surface for our model, so add Ai SubdivType and change it to Catclark.
• We will also want to add some subdivision iterations to smooth the model. Add Ai Subdiv Iterations and increase them to 2.

Bear in mind that each subdivision iteration quadruples the number of polygons. If your object has 2 levels of subdivision iterations set and 4 additional iterations set in Arnold, that's 6 subdiv iterations total and therefore 426936 * 4^6 = 426936 * 4096 = 1.7 Billion polygons.

The number of iterations / levels of subdivision. With Catmull-Clark subdivision, increasing the number of iterations produces a smoother mesh.

Care should be taken when increasing Arnold's subdivision iterations in combination with Maya's Smooth Mesh Preview (3 on the keyboard). Arnold will also render this preview smoothed state in the final image. This may result in a subdivided mesh that far exceeds the necessary amount of polygons required and will result in longer export/render times.

#### Displacement

• We can add more detail to the hair geometry with the use of displacement. Select the Shading Engine for the Hair Shader and connect the 'sven_detailDisp_u1_v4_1' file texture to it.

When using displacement, you should ensure the geometry has enough subdivisions to retain detail from the displacement map.

• Select the hair mesh and go to the Subdivision tab under the Arnold attributes. Change the Subdivision Type to Catclark and increase the number of Iterations to at least 2With Catmull-Clark subdivision, increasing the number of iterations produces a smoother mesh.

Rendering with displacement adds a subtle level of detail to the mesh.

## Rendering

#### Displacement: Killamari wip

• Open the Render Settings window and go to Environment. Connect the Physical Sky we created eariler here by clicking and holding on the  icon to the right. It should appear in the drop down menu.

Physical Sky connected to Background

#### Sampling

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.

#### Displacement: Killamari wip

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.

Thats it. Congratulations, you have successfully converted a scene from mental ray to MtoA! Now go out there and explore new worlds of rendering!

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