chirantan ekbote - department of computer science and...

Brian Arand

John Doolittle

Chirantan Ekbote

Alhad Sapre

Daniel Wilson

The Ohio State University - CSE 682

PLAYBLAST

Used to preview animations

Creates a movie by screen-grabbing your animation one frame at a time during playback

By default the rendered animation is 1/4 the size of the view window.

PLAYBLAST

RENDERING QUALITY Aliasing from point

sampling causes artifacts jagged edges

graininess

flicker

texture crawl

roping

Presets

Anti-

aliasing

Min/Max

Shading

Samples

Global

Sampling

Accuracy

Blur/Soften

Entire

Rendered

Image

Sample further if

contrast with

neighbor pixel

exceeds threshold

(bring out subtle

features)

RENDERING ADVICE

Trade-off between

quality and speed

Render -> Run

Render Diagnostics

for setting

suggestions

Increasing tessellation

Render -> Set NURBS

Tessellation automatically

optimizes each frame based

on distance from camera

RENDERING ADVICE (CONT.) Change object specific attributes

SOFTWARE RENDERING

Done with the CPU.

Slow, but extremely versatile.

Very useful for ray tracers and illumination models.

Primarily used for non real time graphics, such

as cartoons, movies.

HARDWARE RENDERING Faster than software rendering, however it has

lower detail.

Done using the GPU. Modern video cards use shaders to allow for more flexibility.

GPU‟s are specially designed hardware to run floating point operations and simple graphics operations very quickly.

Shaders are small programs run on a per pixel basis.

SOFTWARE RENDERING MAYA

Maya has 2 software renderers.

Built in, and Mental Ray.

Supports all the features found in Maya.

Mental Ray and Maya‟s renderers are roughly

the same with a couple exceptions.

Mental Ray can support HDR images as textures.

Mental Ray supports Caustics, Global Illumination,

Final Gather.

SOFTWARE RENDERING MAYA

Global Illumination

Technique used to capture indirect illumination.

Light bounces off objects until it gets completely absorbed.

Caustics

Light effects that are caused by specular reflected or refracted light, like the shimmering light at the bottom of a pool of water.

Final Gather

Create diffuse scenes where the indirect illumination changes slowly.

MAYA HARDWARE RENDERER

Maya has one hardware renderer, allows for

rendering of lower quality scene very quickly.

Some features are unavailable with the hardware

renderer. Point light shadows, Subdivision

Surfaces, BOT files, Mental Ray area lights.

Some features are not calculated but rather

approximated, such as Maya Area lights.

The stronger the video card, the better quality

images can be produced.

ACCESSING RENDER WINDOW

RENDER OPTIONS

MAYA SOFTWARE Maya (not mental ray) Ray Tracer is not on by

default.

MAYA SOFTWARE(RAY TRACING OFF)

Decent Quality, 2 seconds to render simple

image.

MAYA SOFTWARE(RAY TRACING ON)

High Quality, 5 seconds to render simple image.

MAYA HARDWARE Low Quality, near instant rendering (< 1sec).

MENTAL RAY Quicker than Maya‟s (at least from my experience), and good

quality, with ray tracing. Missing some simple effects however.

RENDER OUTPUT : IMAGE FORMATS

Default : Maya Image File Format(IFF)

Bitmap format :

Image represented using a rectangular grid of pixels

Common formats : Windows Bitmap (BMP), Graphics Interchange Format(GIF), Tagged Image File Format (TIFF)

Vector format :

Use of geometrical primitives to represent image

Mathematical equations for geometrical primitives

Common formats : Scalable Vector Graphics (SVG), Small Web Format (SWF), Vector Markup Language (VML)

RENDER OUTPUT : CHANNELS

Each pixel in bitmap image contains 3 color channels :

Red

Green

Blue

Alpha or mask channel to achieve transparency

Also a depth channel to represent the distance from the camera

Default : 3 color channels and a mask channel

CHANNELSAll

Channels

Red

Channel

Green

Channel

Blue

Channel

BATCH RENDERING

Configuring render

settings

What is Batch Rendering?

HOW TO BATCH RENDER

CHECKING SCRIPT EDITOR

RENDER LAYERS Objects can have different shading and

rendering attributes on different layers

Assign any object to multiple layers with a different material on each layer. This lets you create multiple images for each frame

By assigning different attributes (color, shadow, specular shading, etc) to different layers, you can render them separately. This allows for quick and efficient modification of your scene.

Source: http://www.tutorialized.com/view/tutorial/-Rendering-In-Layers-in-Maya/25157

RENDER LAYERS

Source: Maya Documentation

RENDER LAYERS

RENDER LAYERS

30

MASTER LAYERS AND LAYER MEMBERSHIP

The Master layer contains all the objects and

materials in the scene. There is always a Master layer

in your scene.

When you create new layers, you can make objects

members of only that layer, multiple layers, or all

layers.

Only objects in a specific layer contribute or affect that

layer

You can also change the characteristics of each layer

or object on a layer by creating layer overrides.

There are two types of overrides for attributes: per layer and per object:

Per layer overrides change attributes, characteristics, or material assignments that affect the entire layer

Per object overrides can change the value of an attribute or material assignment on an object in a specific layer on which overrides exist.

LAYER OVERRIDES

GROUPS Too complex?

Try grouping.

GROUPSOutliner:

Hypergraph:

Remember to rename!

GROUPS Select all objects by simply clicking group name

from the outliner, channel box, or hypergraph

views.

GROUPS Translate, rotate, or scale as a group:

A collection of objects or components

Does not alter scene hierarchy

Used to work on multiple items with a single action

Simplifies selection, shading groups, moving

across layers, etc

Sets

Window ->

Relationship

Editors

Right-click in relationship editor to

select objects in scene

Edit -> Create Set

PARTITIONS A collection of related

sets with no overlapping members

Keeps sets separate when overlapping is undesirable

Automatically remove duplicates when moving elements across sets by putting both in a partition first

Change drop-down box to

switch between sets and

partitions

Selecting items can be difficult in a complex

scene due to overlapping geometry that can

obstruct your view.

One way around this problem is to “template”

an object to make it unselectable

Display > Object Display > Template

MAKING AN OBJECT UNSELECTABLE

DISPLAY LAYERS

OR

Open the Channel Box/Layer Editor.

DISPLAY LAYERS

Switch to Layer Editor View.

Make sure „Display‟ is selected.

Go to Layers>Create Empty Layer to make a new layer.

DISPLAY LAYERS

To Rename the layer, double click „layer1‟.

Enter the name and press „Save‟.

DISPLAY LAYERS

Toggle visibility

Display Type

Normal

Template

Reference

Layer Color (Wireframe only)

DISPLAY LAYERS

Display Types

Normal – Displays normally.

Template – Cannot select, doesn‟t render, and

cannot snap to.

Reference – Cannot select, does render, and can

snap to.

DISPLAY LAYERS

Select the layer on the left side of the

Relationship Editor and select the object to add.

DISPLAY LAYERS

In the Relationship Editor go to Edit>Add Selected Items.

DISPLAY LAYERS

Toggle Visibility, Display Type, and Layer Color as desired.

DISPLAY LAYERS

Toggling visibility will effect rendering too!

DISPLAY LAYERS

Useful when working on

internal structure of a

model.

DISPLAY LAYERS

COPIES VS. INSTANCES

Copies are duplicates, but a separate object.

Useful for making template objects, then

altering them as needed.

An instance is a reference to the original object,

so any changes made will be reflected by all

instances.

FILE REFERENCING Powerful feature useful for breaking up

development into parts.

Allows development of one segment to begin much quicker because the previous segment doesn‟t have to be finalized.

Files are not imported, they are referenced, so they can be placed in the scene, moved around, but modified elsewhere.

Files like textures, models, animations, can all be referenced.

Speeds up testing time.

Users can edit the referenced objects in the parent scene without modifying the referenced child scenes (with locking)

Any edits applied to the referenced objects while working within the currently open parent scene remain stored in a reference node.

A reference node is created for each child scene that gets referenced into a parent scene.

The reference node keeps track of how the parent scene uses and modifies objects from the child scene.

FILE REFERENCING

FILE LOCKING

PROXY REFERENCES Substitute one or more file references

Used to temporarily simplify complex scenes by substituting

simpler versions of the objects into the scene

When a scene is simplified in this manner, Maya‟s performance

improves (no overheads of complex objects)

Can only be created for an existing file reference

http://download.autodesk.com/

us/maya/2010help/images/ME

D/Stargate/English/FileRef/com

p_FileRef_ProxyEx1.png

HOW TO USE PROXY REFERENCES

Creating a proxy reference

Loading proxy reference

Removing a proxy reference

Reference

Editor

Proxy

options