Rendering is the process by which we process the snapshot of a scene to its highest quality. This can take a long time, as lighting, shadows, reflections etc are calculated. It can take several hours to render each frame of an animation at high quality.
Currently, Maya uses a rendering engine called Arnold.
Rendering engines are like separate software plugins that work alongside the software – you can download and use others. They use different algorithms for generating the images, some are faster or better than others.
They all share some fundamental functionality though.
SETTING UP A CAMERA.
We rarely want to render from the default viewport camera. Instead, we will make a custom camera, with specific settings, its own movement through the scene, etc.
From the Menu bar, choose Create > Cameras > Camera.
To see through it in one of our viewports, choose Panels > Perspective > Camera 1 from the viewports menu bar.
RENDERING
In the menu bar, go to Arnold > Render to open the render view window.
IPR Icon > real time rendering. This is handy to make small adjustments on the fly but eats up processor power.
RENDER SETTINGS
Render settings should be set before doing your render. As you increase each setting, render time will increase, so strike a balance between desired quality and render time.
Press the Render Settings Icon on the top menu bar – white square icon with a blue gear. Or go to Windows > Rendering Editors > Render Settings
Common Settings first:
Set the File Output type. Usually Png files are good for still images.
Set the Frame Range, if you are rendering an animation.
Set the Renderable Camera to make sure it is the correct viewport that is rendered.
NB: Pngs will be output as a sequence of images, or you can set it to render as a video file. Rendering as images is preferable though– if you have a machine error, any rendered pngs will still be saved, but a video may be corrupted half way through.
Arnold Settings: Sampling > Camera(AA) can be increased for better quality imagery.
System Options: Device Selection > Render Device can be set to GPU if your computer has a decent graphics card.
CAMERA SETTINGS
DEPTH OF FIELD
Depth of field is the range of distances from the camera, in which the image is in focus.
A small depth of field, will have the subject sharp, and everything else blurry.
A large depth of field will keep almost everything sharp. Depending on your subject matter, one or other may be preferable.
FINDING SUBJECT DISTANCE
First, in the menu bar choose Display > Heads Up Display > Object Details.
This shows in white text a variety of parameters.
Select an object in scene you want to be in focus and look at its Distance value. (This is dist from viewport camera - make sure the render camera is selected)
Select the Camera.
In attribute editor, scroll down to Arnold Section.
Check the Enable DOF box
Set the Focus Distance to the Distance value we checked before.
Aperture Size will control how small the depth of field is. The Higher the aperture Size value, the shallower your depth of field, and the blurrier it will be.
NB – There IS a DOF section in the attribute editor, but in this case we leave it to default settings and have Arnold set it up.
HDRI LIGHTING
HDRI lighting uses an image of a 360 light capture, to light your scene from all angles with realistic lighting.
Add an Arnold > Lights > Skydome Light to the scene.
In attribute Editor > Colour, click the checkered box and place a HDRI image file map.
MATERIALS AND SHADERS
Notes from VFX World Vid: https://www.youtube.com/watch?v=sp_TTSAe2nE
A shader is a small program that tells the GPU how to draw an object on the screen and the calculations needed to happen on the object. Shaders are small scripts that contain the mathematical calculations and algorithms for calculating the colour of each pixel rendered, based on the lighting input and the Material configuration.
A material is used to set the value of a parameter that is available from a shader, such as the color, numeric values, and so on. The available options for a material depend on which shader the material is using.
A material specifies one specific shader to use, and the shader used determines which options are available in the material. A shader specifies one or more textures variables that it expects to use, and the Material Inspector in Unity allows you to assign your own texture assets to these these texture variables.
For most normal rendering - by which we mean characters, scenery, environments, solid and transparent objects, hard and soft surfaces etc., the Standard Shader is usually the best choice. This is a highly customisable shader which is capable of rendering many types of surface in a highly realistic way.
There are other situations where a different built-in shader, or even a custom written shader might be appropriate - such as liquids, foliage, refractive glass, particle effects, cartoony, illustrative or other artistic effects, or other special effects like night vision, heat vision or x-ray vision, etc.
ADDING MATERIALS TO OBJECTS
R-Click on Object, choose Assign new material
Arnold > Shaders > aiStandardSurface.
In the Attribute Editor, there is a new tab where you can adjust the material.
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