Modelling and Simulation

Types of Lights

Types of Lights

• In the real world, when light shines on a surface, the parts of the surface facing toward the light source appear illuminated, and the parts of the surface facing away from the light source appear dark. If one object is located between a second object and the light source, the first object casts a shadow onto the second object.

Types of Lights

• Point light• Spot light• Directional light• Ambient light• Volume light • Area lights

Types of Lights

• Point light• A point light simulates rays shining out from one infinitely small point in space.• Point lights emit light uniformly in all directions, like a bare light bulb or glowing

star in space. The illumination and shadows aim out away from the light in all directions, as shown in the following figure.

http://www.youtube.com/watch?v=5FcC5t2w8iI

Types of Lights

• Spot light• Spot lights are a basic staple of most lighting designs in computer graphics.

Spot lights are a popular choice of many artists because they can be controlled conveniently to aim light at a specific target, as shown in the following figure.• The rotation of a spot light can determine where the beam is aimed. You can

also link a "target" to the light so that the light is always oriented toward the position of the target.• A spot light has extra controls and options not found on other types of lights.

Options such as projecting an image map from a light, or making a beam of light visible as if shining through fog, are often best controlled with the beam of a spot light.

http://www.youtube.com/watch?v=GM4-oUOqej4

Types of Lights

• Directional light• A directional light sets a single vector for all its illumination and hits every object

from the same angle, no matter where the object is located. All the shadows cast by a directional light are cast in the same direction and are orthogonal projections of each object's shape. Directional lights can fill very large areas with illumination that appears to be ambient or atmospheric, such as filling in daylight from the sky, providing a quick, effective alternative to global ambience.

http://www.youtube.com/watch?v=cwSHAvKBO7s

Types of Lights

• Ambient light• Ambient light is the widely distributed, "indirect" light that has bounced off (or

been transmitted through) objects in your scene. Ambient light illuminates even the areas not directly lit by another light source. Shadowed areas of a real room are sometimes made visible only by the ambient light. Real-life ambient light is tinted as it bounces around the environment and adds different colors to different sides of objects, based on colors it has picked up from the environment. Real ambient light varies in intensity in different parts of the environment and adds different tones to objects from different angles.

http://www.youtube.com/watch?v=6FS4Fe_NPjQ

Types of Lights

• Volume light• A major advantage of using a volume light is that you have a visual representation

of the extent of the light (the space within which it is bound). The falloff of light in the volume can be represented by the color ramp (gradient) attribute in Maya, which prevents the need for various decay parameters, and also provides additional control. The color gradient is also useful for volume fog.

http://www.youtube.com/watch?v=SKDxPTaNE08

Types of Lights

• Area lights • Area lights are two-dimensional rectangular light sources. Use area lights to simulate

the rectangular reflections of windows on surfaces. Compared to other light sources, area lights can take longer to render, but they can produce higher quality light and shadows. Area lights are particularly good for high-quality still images, but less advantageous for longer animations where rendering speed is crucial.

http://www.youtube.com/watch?v=v_8Ao41UGQ0

Dynamics

• Dynamics• is a branch of physics that describes how objects move. Dynamic animation

uses rules of physics to simulate natural forces. You specify the actions you want the object to take, then let the software figure out how to animate the object.• Dynamic animation lets you create realistic motion that’s hard to achieve with

traditional keyframe animation. For instance, you can make effects such as tumbling dice, waving flags, and exploding fireworks.

Dynamics

• What you can do with Maya Dynamics?• Create, color, and animate particles• Use emitters to launch particles for effects such as steam, fire, rain, fireworks,

and explosions • Use soft bodies to create geometry that bends and deforms when influenced

by a field or struck by a collision object• Use gravity and other force fields to move particles, soft bodies, and rigid

bodies• Create collisions between particles or soft bodies and geometry. You can

make the particles split, emit new particles, or disappear when they collide with geometry

Dynamics

• What you can do with Maya Dynamics?• Use goals to make particles or soft bodies follow other objects or object

components • Use springs to give soft bodies and groups of particles internal structure• Use rigid bodies to create collisions between polygons or NURBS• Use constraints to restrict the motion of rigid bodies• Use built-in dynamic effects to quickly create complex, popular animations

such as smoke and fire• Tune playback efficiency and fix common problems with dynamics• Store dynamic simulations either to disk or to memory

Dynamics

• Particles• Particles are points that display as dots, streaks, spheres, blobby surfaces, or

other items. You can animate the display and movement of particles with various techniques; for example, keys, expressions, and fields such as gravity.

Dynamics

• Particles• A particle object is a collection of particles that share the same attributes. You

can create particle objects containing a single particle or millions of particles. Each particle in a scene belongs to some particle object.

Dynamics

• Particles - Creating particles

http://www.youtube.com/watch?v=NuXXN3ZfaLA

Dynamics

• Particles - Set display attributes

http://www.youtube.com/watch?v=J4vei97GiCg

Dynamics

• Particles - Animate the particle

http://www.youtube.com/watch?v=D1KioBCzzjM

Dynamics

• Particles - Render the particle

http://www.youtube.com/watch?v=Ie4w5QQqUpA

Dynamics

• Particles - Emitters• Emitters generate moving or stationary particles as an animation plays. You can

use emitters to create smoke, fire, fireworks, rain, and similar objects.• Maya includes the following types of emitters:

• Point emitters (directional and omni) emit particles from a position in the workspace or from particles, vertices, CVs, edit points, or lattice points.

• Surface emitters emit particles from random, evenly distributed positions on the outer faces of NURBS or polygonal surfaces.

• Curve emitters emit particles from random, evenly distributed positions of a NURBS curve.• Volume emitters emit particles from a closed volume. You can choose from cube, sphere,

cylinder, cone, and torus.

http://www.youtube.com/watch?v=-wQx0B8b_aw

Dynamics

• Particles - Emitters• Emitters generate moving or stationary particles as an animation plays. You can

use emitters to create smoke, fire, fireworks, rain, and similar objects.• Maya includes the following types of emitters:

• Point emitters (directional and omni) emit particles from a position in the workspace or from particles, vertices, CVs, edit points, or lattice points.

• Surface emitters emit particles from random, evenly distributed positions on the outer faces of NURBS or polygonal surfaces.

• Curve emitters emit particles from random, evenly distributed positions of a NURBS curve.• Volume emitters emit particles from a closed volume. You can choose from cube, sphere,

cylinder, cone, and torus.

http://www.youtube.com/watch?v=fD1FUFFAOOE

Dynamics

• Particles - Emitters• Emitters generate moving or stationary particles as an animation plays. You can

use emitters to create smoke, fire, fireworks, rain, and similar objects.• Maya includes the following types of emitters:

• Point emitters (directional and omni) emit particles from a position in the workspace or from particles, vertices, CVs, edit points, or lattice points.

• Surface emitters emit particles from random, evenly distributed positions on the outer faces of NURBS or polygonal surfaces.

• Curve emitters emit particles from random, evenly distributed positions of a NURBS curve.• Volume emitters emit particles from a closed volume. You can choose from cube, sphere,

cylinder, cone, and torus.

http://www.youtube.com/watch?v=qCMYbYb6Kuk

Dynamics

• Particles - Emitters• Emitters generate moving or stationary particles as an animation plays. You can

use emitters to create smoke, fire, fireworks, rain, and similar objects.• Maya includes the following types of emitters:

• Point emitters (directional and omni) emit particles from a position in the workspace or from particles, vertices, CVs, edit points, or lattice points.

• Surface emitters emit particles from random, evenly distributed positions on the outer faces of NURBS or polygonal surfaces.

• Curve emitters emit particles from random, evenly distributed positions of a NURBS curve.• Volume emitters emit particles from a closed volume. You can choose from cube, sphere,

cylinder, cone, and torus.

http://www.youtube.com/watch?v=20roxUI1bYI

Dynamics

• Particles - Goals• A goal is an object that particles follow or move towards. You can use goals to

give trailing particles a flowing motion that’s hard to generate with other animation techniques. The trailing particles move as if connected to the goal by invisible springs. In the context of goals, soft bodies are considered particles.

http://www.youtube.com/watch?v=AUbSqrKUODg

Dynamics

• Particles - Collisions• You can make particle objects collide rather than pass through polygonal or NURBS

surfaces. Either or both objects can be moving at the moment of collision. Particles cannot collide with other particles. You can use the Dynamic Relationships Editor to reassign collisions between particles and rigid bodies or soft bodies. You can also use the Particle Collision Event Editor to make particles split, emit new particles, die, or run a MEL script when they collide with geometry.

http://www.youtube.com/watch?v=2oOpkFWUmIk

Dynamics

• Fields• You can simulate the motion of natural forces with dynamic fields. For example,

you can connect a vortex field to emitted particles to create swirling motion.• Types of fields

• Air fields• Drag fields• Gravity fields• Newton fields• Radial fields• Turbulence fields• Uniform fields• Vortex fields

Dynamics

• Fields - Air• An air field simulates the effects of moving air. The objects you connect to the

air field accelerate or decelerate so their velocities match that of the air as the animation plays.• You can parent an air field to a moving part of an object to simulate a wake of

air from the moving part. For example, if you have a character walking through leaves or dust on the ground, you can parent an air field to the foot.

http://www.youtube.com/watch?v=4MrkjL0wyR8

http://www.youtube.com/watch?v=dsOc9xQiAc4

Dynamics

• Fields - Drag • A drag field exerts a friction or braking force on an object that’s animated

with dynamic motion.

Dynamics

• Fields - Gravity • A gravity field simulates the Earth's gravitational force. It accelerates objects in a fixed

direction.

http://www.youtube.com/watch?v=dpXBLHvtHcQ

Dynamics

• Fields - Newton • A newton field pulls objects towards it. This lets you create effects such as orbiting planets or

tethered, colliding balls. This field is based on the principle that a mutual attractive force exists between any two objects in the universe, proportional to the product of their masses. As the distance between the objects increases, the force of the pull decreases.

http://www.youtube.com/watch?v=iUqZ3DdHSwo

Dynamics

• Fields - Radial• A radial field pushes objects away or pulls them toward itself, like a magnet.

http://www.youtube.com/watch?v=xMhBMUFgicc

Dynamics

• Fields - Turbulence• A turbulence field causes irregularities in the motion of affected objects.

These irregularities are also called noise or jitter. You can combine turbulence with other fields to mimic the random motion in fluid or gaseous mediums such as water and air.

Dynamics

• Fields - Uniform • A uniform field pushes objects in a uniform direction.

http://www.youtube.com/watch?v=ETPVPNngAlY

Dynamics

• Fields - Vortex• A vortex field pulls objects in a circular or spiraling direction. You can use this field with particles

to create effects such as whirlpools or tornados.

http://www.youtube.com/watch?v=-AKj9FiAQ1c