six types of light sources
attributes to light
shadows
shading
lighting tips and tricks
Ambient. brightens all part of the scene uniformly
useful for simulating both direct and indirect light.
Directional. Even illumination of a scene using parallel rays of light.
useful for extremely far away sourses. sunlight
Point. light radiates in all direction from a single point.
ideal for omni directional sources. eg. lightbulb
Spot. creates a cone of light in one direction
useful for beams of light. ex. flashlight, lighthouse.
Area. 2D rectangular light sources
useful for windows, ceiling lights. Longer render time.
Volume. Light fills a 3D shape. Sphere, cylinder, etc.
useful for a visual represention of the extent of the light.
THREE POINT LIGHTING
Key light. Main source illuminating the object
Secondary (fill) light. highlight details of the object.
Black light. Distinguishes the object from the background.
ATTRIBUTES OF LIGHT
-Intensity. How much light emitted from the light source.
-Cone Angle decay. How much light diminishes away from the source light. E.g. Fall off.
-Cone Angle. Width of the lights cone of influence - area outside cone not illumunated.
-Penumbra Angle. Fall off at edge of cone angle - more gives a softer edge to the light source/ cone.
Drop off. How much the light diminishes at the outer edges.
Colour. Set an RGB colour for the light.
Ways to use lights
Look to photographers for good techniques.
Think with balance
Avoid the overly dramatic
Look at natural lighting
Avoid natural hues
Normally only need a few lights
Avoid disco colours and effects.
Shadow Effects
Hard shadows Harsher edges.
Soft shadows Softer and more realistic edges.
Fall-out more colour gradient. lighter at the top.
Shading
Shading is a combination of the basic material of an object and any textures that are applied to it.
Blinn. Simulates diffuse reflection and soft specular highlights
Used for metallic surfaces
Lambert. Simulates diffuse reflection, no specular highlights
Matte surfaces.
Phong. Simulates diffuse reflection and hard specular highlights.
Faster render time than Blinn.
Useful for shiny surfaces.
Commentaires