Chirantan Ekbote - Department of Computer Science and...
Transcript of 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
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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