Springs dont move the particles CVs vertices or points
Either no force is acting on the particles or the restLengthPS is turned on but you didn't set any values for it. By default, each spring's rest length equals its original length. It won't move unless an external force is applied to it. A pair of identical particle grids with springs are shown here after several frames of play. The particles on the right fail to move because restLengthPS is turned on while the default values are in use. To make the springs take effect, do the appropriate action...
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. Tentacles created by Jason Schleifer Tentacles created by Jason Schleifer Understanding goals on page 162 Creating goals on page 164 Editing goal attributes on page 165 Animating...
Dynamic Relationships Editor
The Dynamic Relationships Editor lets you connect and disconnect dynamic relationships between objects and fields, emitters, and collisions. This chapter describes how to use the Dynamic Relationships Editor, including Understanding the Dynamic Relationships Editor on page 325 Making connections on page 326 Example Connecting and disconnecting gravity on page 327 Connecting to selected fields or emitters of an object on page 330
H
Hardware Render Buffer 334 hardware rendering particles 17, 333 Hardware Texture Cycling Options 382 Hide Non-Soft Object 175, 176 Hinge rigid body constraint 226 Image Format attribute Image Output Files attributes 336 impulse setting keys 211 Impulse Position X, Y, Z 203 Impulse X, Y, Z 203 Incandescence attribute Particle Cloud Attributes 343 incandescencePP 390 Inherit Color 103 Inherit Factor 87, 390 Inherit Opacity 103 Inherit Rotation air field 124 Inherit Velocity air field 124 particle...
Example Lkv
An emitter shoots particles up in a 150-frame animation. The following steps show how to control the velocity of the particles by keying Current Time. 1 Select the emitted particle object not the emitter . 2 In the Channel Box, click the Current Time attribute, then right-click and select Break Connections. 3 Set keys for Current Time at the following frames At the beginning of the animation frame 0 , the Current Time of the emitted particles is synchronized with the scene time. Both have the...
Soft Bodies
You can recreate a geometric object as a flexible object called a soft body. You can use various animation techniques to make the soft body bend, ripple, and bulge like soft objects in nature. Soft body flag created by Rob Tesdahl Soft body flag created by Rob Tesdahl This chapter describes soft bodies, including Understanding soft bodies on page 172 Creating soft bodies on page 172 Special uses of soft bodies on page 176 Duplicating soft bodies on page 182
Emitter attributes and Power Animator equivalents
If you are a Power Animator user, the following table summarizes the emitter attributes and their equivalent settings in Power Animator. Determines the type of emitter. There is a new choice, Volume. When turned on in surface emitters, adds parentU and parentV attributes to the particle shape. If turned on the default , object size affects number of particles emitted per frame. If turned off, it does not. All except volume. Always turned off in Volume emitters. Turn off to make Rate work as it...
Setting Particle Opacity
You can give particles any amount of transparency. For software render particle types Cloud, Blobby Surface, Tube , you must set a transparency attribute in the material that controls the particle object's color. See Using Maya Rendering for details. Do not add a per object or per particle opacity attribute to a software render particle type. The attribute value has no effect when you software render the scene. For hardware render particle types, you can add a per object or per particle opacity...
Info
Maya effects are built-in programs that make it easy for you to create complex animation effects such as smoke and fire. Each Maya effect offers many options and attributes for tuning the results. This chapter describes how to use Maya effects, including Surface Flow on page 290
Example
Suppose you emit particles at a rate of 50 per second. If you display the emitted particles as the Numeric render type, you might see the following particles after you play seven frames. If you set Level Of Detail of the emitted particles to 0.5, the emitted particle object ignores roughly half the emitted particles. The following particles are displayed after you rewind and play seven frames. Maya removes particles and particleId values randomly. This is useful if you create expressions with...
The Using Maya series
The Using Maya books describe how you can use Maya's user interface to create professional 3D graphics animations and visual effects. Each book is devoted to a different area of the software. The Using Maya series includes these books provides a guide to Maya's user interface and basic tools. Using Maya Essentials also defines a number of concepts that are common to all of Maya. Using Maya Essentials was called Using Maya Basics in previous releases. describes Maya's spline modeling system and...
R
radial field 134 Radial Name 134 Radial Type 134 Radius 393 Blobby Surfaces 28 Clouds 30 Particle Spheres 26 Radius0 31 , 393 Radius1 31 , 393 radiusPP 393 mapping to an existing 56 rampAcceleration 42, 46, 393 rampPosition 42, 46, 393 ramps breaking connection 57 customizing per particle control with 52 setting per particle attributes 42, 45 rampVelocity 42, 46, 393 Random Particles 157 Random Direction attribute 87 random motion 135 Random Motion Speed Flow effect 287 Random Radius 294 Random...
Emitters
Emitters generate moving or stationary particles as an animation plays. You can use emitters to create smoke, fire, fireworks, rain, and similar objects. This chapter describes how to work with emitters, including This chapter describes how to work with emitters, including Understanding emitters on page 74 Creating emitters on page 75 Editing attributes of an emitter on page 79 Editing attributes of emitted particles on page 91 Duplicating emitters on page 94 Connecting emitters and particles...
To make an object move with a dynamic parent
1 Select the object to be parented. This parents the object to an empty group transform node. 3 Select Windows gt General Editors gt Connection Editor. 4 Load the particle shape of the dynamic parent into the Connection Editor's left side. Load the group object's transform node into the right side. 5 Connect World Centroid in the left side of the Connection Editor to Translate in the right side. This provides the dynamic parent's World Centroid worldCentroid values to the Translate attributes...
Using Mayas online documentation
For your convenience, the Maya documentation is online in html format. This help requires version 4 or higher of either Netscape Communicator or Internet Explorer. We include the complete Maya Unlimited documentation set, no matter what version of the software you have purchased. To allow you to print copies of the documentation, we've provided PDF files of most documents. These files require the Adobe Acrobat reader. To print the online books, insert your Maya CD, navigate to the pdf...
Creating Goals
You can make a particle object move towards one or more goal objects with the following procedures. Note that you can create a soft body with its original geometry as its goal see Creating soft bodies on page 172 . If you make a trimmed NURBS surface a goal object, all its CVs become the goal, including the CVs where the trimmed area exists. To correct this, convert the NURBS surface to polygons with Edit Surfaces gt NURBS to Polygons and then add the goal. To connect a particle object to a...
To vary emission from a NURBs or polygonal point emitter
1 Finish modeling the geometry before adding a point emitter. 2 Select the emitting geometry. 3 Select Particles gt Per-Point Emission Rates. 4 Select the emitting object's shape node. 5 In the Extra Attributes section of the Attribute Editor, open the emitterName Rate PP section. For the emitterNameRatePP attributes, enter values in the Attribute Editor boxes corresponding to the CVs, vertices, edit points, or lattice points. To learn which box corresponds to a point, experiment with a large...
Rigid Body Constraints
Rigid body constraints restrict the motion of rigid bodies. The constraints simulate the behavior of real-world items you're familiar with pins, nails, barriers, hinges, and springs. You can constrain rigid bodies to a position in your scene or to other rigid bodies. If you create a constraint on an object, Maya automatically makes the object a rigid body. This chapter describes how to work with rigid body constraints, including Creating a Nail constraint on page 224 Creating a Pin constraint...
To emit particles into a volume shape
1 Select Particles gt Create Emitter . 2 Under Basic Emitter Attributes, set the Emitter Type to Volume. 3 Under Volume Emitter Attributes, click Volume Shape and select a shape from the menu. 4 Set the Volume Emitter attributes as desired. See Volume Emitter Attributes on page 85 and Volume Emitter Attributes on page 85 for information on the volume emitter attributes. The implicit shape of the volume emitter is displayed on the screen. You can move, rotate, scale, or shear the emitter.
To view hardware rendered particles from within Maya
1 In the Hardware Render Buffer, select the sequence of images you want to view from the Flipbooks menu. The hardware rendered particles are displayed in an fcheck display window. See the online documentation for fcheck in the Maya Rendering Utilities online documentation. The play repeats continuously unless you specify otherwise with an fcheck option. You can specify fcheck options as described in To set fcheck options on page 341. 2 To close the fcheck display window, press Esc.
Gravity field
A gravity field simulates the Earth's gravitational force. It accelerates objects in a fixed direction. You can set the following attributes in gravity fields Gravity Field Attributes Sets the strength of the gravity field. The greater the magnitude, the faster the objects will accelerate in the direction of the gravitational force. Sets how much the strength of the field diminishes as distance to the affected object increases. The rate of change is exponential with distance the Attenuation is...
Shatter
Shatter duplicates an object and breaks the duplicate into multiple pieces called shards. Depending on the type of shard you choose to create, you can move the shards with dynamic forces or keyframe their movement. Shatter provides three methods of breaking the object Surface shatter breaks the selected object along polygonal boundaries. You can use surface shatter to break an object into individual polygons. Select the object you want to shatter. You can select a NURBS or polygonal object. It...
To create a Particle Sampler info node
1 Create your particles and set the Render Type Cloud, Blobby, or Tube. 2 Determine which particle attribute you want to use to drive a shader attribute. 3 Add that attribute to the particle shape, if necessary. 4 Select the particles and display the Attribute Editor. Click the Attribute Editor tab for the shader, and find the shader attribute you want to drive with the particle attribute. 5 Click the map button next to that attribute to display the Create Render Node window. 6 In the Create...
Tip Fam
We used an expression in this example to achieve a specific effect. However, you don't have to use expressions with the Particle Sampler Info node. You can also use a ramp, which will give you a different effect. 8 In the particleCloud Attribute Editor, click the map fl J button next to noise. 9 The Create Render Node window, click the Utilities tab and click the Particle Sampler Info button under Particle Utilities . 10 Connect the Particle SamplerInfo node's parentU to Noise, and connect...
Uniform field
A uniform field pushes objects in a uniform direction. You can set the following attributes in uniform fields Sets the strength of the uniform field. The larger the number, the stronger the force. A positive number pushes the influenced object away. A negative number pulls the object toward the field. Sets how much the strength of the field diminishes as distance to the affected object increases. The rate of change is exponential with distance the Attenuation is the exponent. If you set...
Drag field
A drag field exerts a friction or braking force on an object that's animated with dynamic motion. You can set the following attributes in drag fields Drag Field Attributes Sets the strength of the drag field. The greater the magnitude, the greater the braking force on the moving object. Sets how much the strength of the field diminishes as distance to the affected object increases. The rate of change is exponential with distance the Attenuation is the exponent. If you set Attenuation to 0, the...
Emitting killing or splitting particles upon contact
You can make particles emit new particles, die, or split into multiple particles when they collide with geometry. You can also execute a MEL script upon collision. The actions that occur after contact are called events. Initial particle object before collision After collision, new particles are emitted. To create a particle collision event 1 Select the particle object you want to be affected by the event. 2 Make the particles and geometry collide. 3 Select Particles gt Particle Collision...
Instancing strokes from Paint Effects
You can use strokes from Paint Effects as instanced objects for particles. The image below was created using Paint Effects strokes instanced to particles. See lt A target top gt Using Maya Paint Effects lt A gt for information on painting in your scene, and see Instancing animated geometry to particles on page 60 of this book for information on instancing.
Tube
The Tube render type displays particles as tubes. Tubes appear only in software rendered images. 2 In the Attribute Editor, set Particle Render Type to Tube. 3 To add default Particle Render Type attributes that let you tune the appearance, click the Add Attributes For Current Render Type button. Sets a radius for the tube at its starting point. See the figure that follows. Sets a radius for the tube at its ending point. Scales the length of the tube. This value is multiplied by the particle's...
Using the Particle Sampler Info node
The Particle Sampler Info node provides particle shape attributes to either a particle shader, texture, or texture placement node for use in software rendering. When you use a Particle Sampler Info node, you connect one or more of its outputs to attributes of a particle shader or texture placement node. This tells the shader to get the per-particle information from the Particle Sampler Info node. It also tells the Particle Sampler Info node which attributes to get from the particle shape. The...
Assigning an identical image sequence to all sprites
When you added default Particle Render Type attributes for sprites in a prior step, Maya added a Sprite Num attribute to the particle object. Sprite Num sets which files are cycled from the pool of files specified by Start Cycle Extension, End Cycle Extension, and By Cycle Increment. More specifically, Sprite Num is an index into the pool of files. For example, suppose you have a file sequence starting with Smoke.0. If you set the Start Cycle Extension to 0, the End Cycle Extension to 29, and...
To create a Hinge constraint
1 Select the one or two rigid bodies you want to constrain. 2 Select Soft Rigid Bodies gt Create Constraint to display the options window. 3 For the Constraint Type, select Hinge. 4 If you are constraining two rigid bodies and want them to penetrate each other rather than collide upon contact, turn on Interpenetrate. If you turn on Interpenetrate, playback of rigid body animation is faster. 5 Turn on Set Initial Position and enter X, Y, and Z values for the position. If you don't turn on Set...
To instance a sequence of objects to particles
2 Select Particles gt Particle Instancer . The Particle Instancer Options window appears. The selected source geometry is listed in the Instanced Objects list. 3 To instance different objects at different particles, include them all on the list. or To instance a sequence of objects, list the objects in the order you want them to appear in the sequence. Use the Move Up and Move Down buttons to change the order of the objects. Use Add Selection if you want to add selected objects to the list. Use...
Numeric
The Numeric render type displays the current values of any attribute of the particle object. This is useful when you want to know the value of an attribute such as velocity at a certain frame. By default, Maya displays particle ids for the Numeric render type. 2 In the Attribute Editor, set Particle Render Type to Numeric. 3 To add default Particle Render Type attributes that let you tune the appearance, click the Add Attributes For Current Render Type button. Attribute Name Name of the...
Setting volume control attributes
In the Attribute Editor and the Create Emitter option window, attributes not applicable to a volume shape are dimmed. However, the Channel Box does not support dimming. We recommend you use the Attribute Editor instead of the Channel Box to edit volume field attributes until you become familiar with the attributes that apply to each volume shape. 1 Select the field and display the Attribute Editor. You can select the particle object connected to the field and the Attribute Editor displays a tab...
Setting goal weight on a per object basis
When you add a goal to an object, Maya adds a corresponding goal weight attribute to the trailing particle object. The goal weight sets how much all particles of the trailing object are attracted to the goal. You can set the goal weight before you create the goal using the Goal options window, or you can adjust the goal weight afterwards using the Attribute Editor. You can set goal weight to a value between 0 and 1. A value of 0 means that the goal's position has no effect on the trailing...
Warning when you delete rigid body connections
Warning Cannot disconnect 'rigidBody1.choice' from 'rigidBody_tx.selector'. To force the disconnection, set the 'Allow Disconnection' attribute in the attribute editor. In the dependency graph, a rigid body node controls the transform node of the rigid body object with connections through several choice nodes. The choice nodes let you key passive rigid body Translate and Rotate attributes so you can switch from keys to dynamic influences and vice versa. Maya usually lets you break the...
General Options
Position of the instanced objects. The default setting is worldPosition. Maya interprets the values of the selected attribute in the local space of the Instancer node, not in world space. So if you move the Instancer node, you move the instances also. If you are an API developer, note that you can write an API to send point data to the Instancer. Scale of the instanced objects. The default value is 1, 1, 1. Shear of the instanced objects. The default value is 0, 0, 0. Sets whether display of...
Volume Axis field
The Volume Axis field lets you move particles in various directions in a volume. The motion imparted on the object is relative to the axis of the volume. You can use the Volume Axis field to create effects such as particles flowing around obstacles, solar flares, mushroom clouds, explosions, tornadoes, and rocket exhaust. For example, you can specify the speed at which particles move around the central axis of a volume. If you use a a cylinder volume shape, this can create swirling gaseous...
To disable dynamic calculations for selected particles
For emitted particles, select the emitted particles rather than the emitter. For a soft body, select the geometry or the particles. 2 In the General Control Attributes section of the Attribute Editor, turn off Is Dynamic. If you have not keyed, parented, or otherwise controlled the transform attributes of a particle object, turn off Emission In World to quicken dynamic calculations for the object. When Emission In World is on, Maya makes extra computations to convert world space to object space...
Radial field
A radial field pushes objects away or pulls them toward itself, like a magnet. You can set the following attributes in radial fields Sets the strength of the radial field. The larger the number, the stronger the force. A positive number pushes objects away. A negative number pulls objects toward the field. Sets how much the strength of the field diminishes as distance to the affected object increases. A value of 0 keeps the force constant over distance. Specifies how the radial field's effect...
The Maya Technical Library
When you're ready to use Maya to its fullest potential, you'll want to explore the technical library. These documents tell how to use Maya's powerful command language and expressions. They also provide information that will help you use Maya with other software packages. The books in the Maya Technical Library are not included in a printed document set. However, html files for all of these documents are provided on your product CD for online viewing. PDF files are also provided unless otherwise...
Vortex field
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. You can set the following attributes in vortex fields Vortex Field Attributes Sets the strength of the vortex field. The larger the number, the stronger the force. A positive number moves the influenced object counterclockwise. A negative number moves the object clockwise. Sets how much the strength of the field diminishes as distance to the...
Obtaining world position velocity and centroid
A particle object's position, velocity, and centroid attributes contain local space values. The centroid of a particle object is the average position of its particles. There are times when you need to know world space values for a particle object. For example, suppose you apply gravity to a particle object to make it fall through a glass floor. You also key the particle object's Rotate Y attribute to make it rotate around the origin's Y axis as it falls. Suppose you need to know the exact world...
Creating lightning
When you create lightning, you set the Lightning Creation Controls in the Lightning options window to determine certain aspects of the lightning. You cannot change these once the lightning is created. If you want to change them, you must delete the lightning and recreate it. You can also set the Lightning Attributes in the options window. These attributes can be edited after you create the lightning. 1 Add the objects to the scene that you want the lightning to extend between. 2 Select the...
Avoiding unexpected particle penetration of geometry
In repeated or numerous collisions, particles might pass through the geometry because of insufficient collision detection sensitivity. You can increase sensitivity to avoid this problem. To adjust the collision detection sensitivity 2 In the Attribute Editor's Collision Attributes section, increase Trace Depth. The Trace Depth sets the maximum number of collisions Maya can detect for the object in each animation time step. For instance, with a setting of 2, Maya checks twice in a frame. Any...
A polygonal or NURBS soft body with springs slows playback and has unrealistic
If you put springs on a polygonal soft body or a NURBS soft body with many vertices and particles , your animation will play slowly and the springs might contract and expand unrealistically. To avoid this problem, put springs on a low-resolution copy of the object as follows 1 Duplicate the polygonal or NURBS object with default options. Note that copy must exist at the same locations as the original for the entire animation. 2 Decrease the surface resolution of the object to roughly 10-50 of...
Tips 1
You can key the emitter position or parent the emitter to a moving object the same as for any other object. See Using Maya Animation for information on setting keys. If you see clumps of particles or irregular emission direction when you animate the motion of an emitter, try the following remedies to smooth the emission Make sure the Playback Speed is set to Free in the Playback Speed pulldown in the Window gt Settings Preferences gt Preferences gt Timeline window. Increase the Rate or Max...
Using the Particle Cloud shader
The particle cloud shader is a volume material that you can assign to particles with a Cloud render type to achieve effects such as gas or clouds. This section describes the attributes you can modify in a particle cloud shader. For information on creating and assigning materials, see Introduction to Materials in the Rendering Reference online documentation.
How lifespan is determined
A read-only per-particle attribute called finalLifespanPP stores the final result of lifespan computations no matter what mode you are using. The particle shape uses finalLifespanPP to kill particles and to drive ramps. In Constant or Random Range mode, the value computed from lifespan lifespanRandom is stored for each particle. In lifespanPP only mode, the value of lifespanPP is stored. In Live Forever mode, a maximum-value float is stored. You cannot set the value of finalLifespanPP yourself...