Learn How To Render Like Pixar
3D World UK|April 2020
Learn How To Render Like Pixar
Unlock the secrets of Pixar's RenderMan with VFX artist Rusty Hazelden
Rusty Hazelden

For over 30 years Pixar’s RenderMan has been used in the film industry to render movies featuring groundbreaking animation and visual effects.

In this four-part tutorial series, we’re going to discover how to harness the power of RenderMan by taking an animated shot from start to finish, and learn all of the techniques required to create a photorealistic animation using Pixar’s RenderMan for Maya.

Using RenderMan to create photorealistic renders has never been easier. In this series we’re going to begin with untextured objects in Maya, and learn how to create surface materials, set up lights, adjust camera attributes, customise the render settings, and batch render the final animation to disk using Local Queue as a series of EXR images. By the end of the project, you will have a solid understanding of the workflow used to light and render a dramatic night-time scene using RenderMan for Maya. Along the way, you will learn numerous tips and tricks that will come in handy on your next RenderMan project!

In part three of this tutorial series, we’re going to explore the powerful Alembic workflow in RenderMan and find out how to assign materials to Alembic archives using the Dynamic Rules Editor. Once we finish texturing the objects, we’re going to learn how to create a dramatic lighting setup that evokes the feeling of a work light outdoors at night.

01 OPEN THE MAYA SCENE

Let's continue from where we left off in the previous part. Go ahead and open your Maya scene from the end of part 2. Select the R_Nail object in the Outliner. Switch to the Rendering menu set, and from the Lighting/Shading menu, select Assign Existing Material>Nail_Material. This will apply the Nail_Material to the R_Nail object. The rest of the nails scattered throughout the scene are loaded from an Alembic file.

02 CHECK THE ALEMBIC SETTINGS

Select the Scattered_Nails object in the Outliner, and then switch to the Scattered_NailsShape tab in the Attribute Editor. This tab contains many useful settings that will affect how the Alembic file is rendered in RenderMan. There are a few important settings that you should always double-check before rendering an Alembic file. Expand the Render Stats section and make sure that Visible in Reflections and Visible in Refractions are both enabled. Then expand the RenderMan section and make sure the Render Alembic Cache checkbox is enabled.

03 THE DYNAMIC RULES EDITOR

This Alembic file only contains static nail geometry. That means the nail models that are being loaded from this Alembic file are resting on the ground and not moving. If you have an Alembic file containing animated geometry, you may need to enable the Use Global Time checkbox to load animation data. To assign a material to an Alembic file, we're going to use the Dynamic Rules Editor which can be found in the RenderMan shelf. Click on the Dynamic Rules Editor icon to open the editor.

04 CREATE A DYNAMIC RULE

Click the Plus icon in the Dynamic Rules Editor to create a new rule. A rule is used to link a RenderMan material in the Maya scene with an object contained in an Alembic archive stored on disk. Alembic archives are a form of file referencing. The Alembic file is read by RenderMan at render time, but the actual geometry data is not stored in the Maya scene file. The first text field is for the Material ID, which is also known as the payload. Type in ‘Nail_SG’ and press enter. This is our nail material.

05 INSPECT ALEMBIC ARCHIVES

The next text field is for the rule that will select specific objects contained within the Alembic archive. This is also called the Expression field. The Alembic file contents are listed in the Inspect Alembic section of the Attribute Editor. Double-click on the Scattered_Nails entry at the top of the list in the Attribute Editor. Copy this text, and then click on the Expression field in the Dynamic Rules Editor. Type in a forward slash ‘/’ and paste the text ‘Scattered_ Nails’ into the Expression field. Press enter to complete the rule. After modifying a rule you'll need to restart the IPR render to update the Maya Render View. Then close the Dynamic Rules Editor.

06 LIGHT THE SCENE

articleRead

You can read up to 3 premium stories before you subscribe to Magzter GOLD

Log in, if you are already a subscriber

GoldLogo

Get unlimited access to thousands of curated premium stories, newspapers and 5,000+ magazines

READ THE ENTIRE ISSUE

April 2020