RENDERING, CAMERAS & LIGHTING
CGDD 4113
Jeff Chastine
RENDERING
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The process of converting your scene into a 2D image
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For gaming, we don’t care about it that much (but still important)
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Click on a View (the header) and then use menus and shelf
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For this class, use standard menu bar
• Open rendering view
• Render Single Frame*
• IPR Rendering
• Render Settings*
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After rendering, you have the option to save the image (File->Save Image)
COMMON SETTINGS
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File Output
• Prefix
• Image format
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Resolution (e.g. 640x480, 72 dpi)
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Frame range (for animations)
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Camera (front, side, persp)
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Aspect ration (HD)
MAYA SOFTWARE SETTINGS
CAMERA SETTINGS
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In each view, there’s a camera icon
•
Can set options like:
• Depth of field
• Background color
• Angle of view
• Focal length
• Near/Far clip plane
CAMERA SETTINGS
IMAGE PLANES
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Using an image as the background color
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Image always faces the camera (orthogonal)
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Can animate it, but doesn’t move if camera turns
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Instead use a Skybox
(or Sky Dome)
LIGHTING
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Several kinds of lights – hardest part of realism!
• Default* – if no other lights, this one’s there (to the upper-left of camera)
• Ambient – only affects ambient component of material
• Directional light - parallel rays come from infinitely far away
• Point* - a lamp
• Spotlight* - a spotlight (duh!)
• Area* – a rectangular light is the source (not just a point). Soft edged shadows
• Volume – advanced. We won’t be using it here.
• Global Illumination (Radiosity) – algorithm, not light. Patch-based. Mental Ray only.
•
Shadows – must turn them on per light and in render settings!
* Attenuated (falls off with distance). Typically 1/d^2
http://krypton.fhda.edu/~bpuckett/gallery/doit_urself/Maya/Lights_and_Lighting
DEFAULT LIGHT
(WITH RAYTRACING AND SHADOWS TURNED ON)
AMBIENT LIGHT
(WITH INTENSITY AT 1.000 TO DEMONSTRATE IT – SHADOWS OFF)
DIRECTIONAL LIGHT
•
Has two parts (position and direction)
•
Separate with the ‘T’ key
DIRECTIONAL LIGHT
(RAYTRACING, SHADOWS ON)
POINT LIGHT
SPOT LIGHT (2 PARTS)
(PENUMBRA =5.0, CONE ANGLE=50.0, NO DECAY)
AREA LIGHT (2 PARTS)
ABOUT SHADOWS
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Two common kinds of shadows
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Raytrace
• Takes longer
• Usually gives hard edges
• Is exact
•
Shadow maps
• Usually faster
• Must specify resolution (default 512, which is bad)
• Gives softer edges
• Edges can be jagged
ABOUT SHADOWS
512
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