Connect shards to fields

 
 
 

Once you’ve shattered your object, you can move the shards with the move tool and keyframe the motion, or you can connect the shards to a Dynamics field and let the field move the shards.

Note

If you add a field to shards that are shapes, the software automatically converts the shapes to active rigid bodies with collision on. This will cause interpenetration problems with the rigid bodies because the shard’s edges overlap each other. Turning off collisions for the rigid bodies solves this problem.

To connect rigid body shards to fields

  1. In the Outliner, expand the shatter node.
  2. Highlight the shards you want affected by the field.
  3. From the Dynamics menu, select Fields > fieldname.

    The field is created and connected to the shards.

To connect soft body shards to fields

  1. In the Outliner, expand the shatter node.
  2. Expand the shard you want affected by the field and select the shard particle shape (shard#Particle).

    If you want all the shards to be affected by the field, you must select the particle shape for each shard.

  3. From the Dynamics menu, select Fields > fieldname.

    The field is created and connected to the shards.

Link original surface to shards

When you turn on the Link to Shards option, Maya makes several connections from the original surface to the shards. This option lets you control the visibility of the original surface and the shards with one attribute on the original surface’s transform node.

Shatter attribute

When you use the Link To Shard option, a Shatter attribute is added to the transform of the original object. The Shatter attribute toggles the visibility of the shattered surface with the visibility of the original surface. When the Shatter attribute is on, the shattered object is visible. When the Shatter attribute is off, the original object is visible. Shatter is turned on by default when you create the shatter so you can see the shattered object.

Rigid bodies

If you have selected rigid bodies with collisions off as the post-operation, and turned on Link To Shards, the shatter node is parented to the original object and the Shatter attribute is connected to the active/passive attribute of the rigid body.

If you’ve turned on the Make Original Surface Rigid option, the Shatter attribute is also linked to the Ignore attribute of the original rigid body. When the Shatter attribute is turned on, the Ignore attribute of the original object is also turned on. This causes the original surface to be ignored in the rigid solver and prevents the original surface from influencing any other rigid body once the shatter object is visible.

When the Shatter attribute is turned off, the shards become passive rigid bodies. When shatter is on, the shards become active rigid bodies so fields will affect them. You can use this to create an object that shatters when it hits a surface.

To shatter a rigid body on impact

  1. Create a surface for the object to hit and make it a passive rigid body.
  2. Set the collision layer of the passive rigid body to -1.

    This sets it to the universal collision layer that allows it to collide with every rigid body.

  3. Create an object to shatter.
  4. Select Effects > Create Shatter > .
  5. Select the type of shatter you want.
  6. Set the Post Operation to rigid bodies with collisions off.
  7. Turn on Link To Shards.
  8. Turn on Original Surface Rigid.
  9. Click Create.
  10. In the Outliner, expand the object you shattered to display the shatter node. Expand the shatter node. Select the shards and Ctrl-click (Linux and Windows) or Command-click (Mac OS X) to select the original object.
  11. From the Dynamics menu, select Fields > Gravity.
  12. Select the original object. At the start of the animation, keyframe the Shatter attribute to off.

    The original object becomes visible and an active rigid body.

  13. Play the animation until the object is about to hit the passive rigid body surface.
  14. Keyframe the Shatter attribute on.

    The shattered object becomes visible and the shards become active rigid bodies.

  15. Rewind and play back.

Soft bodies

If you have selected a soft body post operation, and turned on Link To Shards, the shatter node is not parented to the original object. The Shatter attribute is added to the original object’s transform node and controls the visibility. When the Shatter attribute is turned on, the shattered object is visible. When the Shatter attribute is turned off, the original object is visible.

A goal weight attribute, which controls the goal weights of the soft body particle shapes, is also added to the transform of the original object. This “control” goal weight is in addition to the goal weight that is added to the particle shape of the shard.

When the Shatter attribute is turned off, the goal weight of the particle shape of the shards is set to 1.This causes the shattered object to follow the goal object, which is a copy of the original surface, when it is not visible. When the shatter attribute is turned on, the shattered object becomes visible and the goal weight of each of the particle shapes is set to the value of the “control” goal weight attribute of the original surface. These attributes are connected with an expression.

You can use this to create a soft body that explodes.

To explode a soft body

  1. Create an object to shatter.
  2. Select Effects > Create Shatter > .
  3. Select the type of shatter you want.
  4. Set the Post Operation to soft bodies with lattices and goals.
  5. Turn on Link To Shards.
  6. Click Create.
  7. In the Outliner, expand the shatter node, then expand the softBodyLattices# node.Ctrl-click (Linux and Windows) or Command-click (Mac OS X) To select each lattice of each shard (shatter#Lattice).
  8. From the Dynamics menu, select Fields > Radial.
  9. Select the original object. At the start of the animation, keyframe the Shatter attribute to off.

    The original object becomes visible.

  10. Select a frame at which you would like to explode the object.
  11. Keyframe the Shatter attribute on.

    The shattered object becomes visible and the shards become active rigid bodies.

  12. Rewind and play back.

Change the extrusion value of a shard

Once you’ve created a shatter with an extrusion, you can change the extrusion value for all the shards or for individual shards using the Local Translate Z attribute of the shard shape.

If you haven’t created the shatter using an extrusion, an extrusion node is not connected to the shards.

To change the extrusion value of a shard

  1. Select the shard.
  2. If the shard is a rigid body or a shape, In the Channel Box, select shardShape#.
  3. In the Channel Box under INPUTS, select polyExtrudeFacet#.
  4. Scroll down in the Channel Box to locate the Local Translate Z attribute.
  5. Enter a value to change the extrusion.

Set goal weights on soft-body shards

The goal weight influences how much a soft body follows the goal object. You can set the goal weight to a value between 0 and 1. A value of 0 means that the goal’s position has no effect on the soft body. A value of 1 moves the soft body to the goal object position immediately.

Values between 0 and 1 cause the soft body to move toward the goal as if bound to it by an elastic spring. The closer to 1, the greater the influence the goal object has on the position of the shards. The goal weight value is 0 by default, which means the goal’s position has no effect.

When you select a post-operation option that creates a goal weight but you don’t turn on Link to Shards, a goal weight attribute is not created on the original shape. The goal weight is an attribute of the particle shape so you must select the particle shape in each shard of the shatter node to display the goal weight attributes.

To set the goal weight on soft-body shards with goals

  1. In the Outliner, expand the shatter node.
  2. Expand the shard whose goal weight attributes you want to set.
  3. Select shard#Particle.
  4. Do one of the following:
    • In the Attribute Editor, display the Goal Weights and Objects attributes.
    • Scroll down the Channel box to locate Goal Smoothness, Goal Weight[0], and Goal Active[0].
  5. Enter values for the goal weight attributes. For complete information on setting goal weight attributes, see Goals.

To set the goal weight on shards with soft-body lattices and goals

  1. In the Outliner, expand the shatter node.
  2. Expand the softBodyLattices# node.
  3. Expand the shatter#Lattice whose goal weight attribute you want to set.
  4. Select shatter#LatticeParticle.
  5. Do one of the following:
    • In the Attribute Editor, display the Goal Weights and Objects attributes.
    • Scroll down the Channel box to locate Goal Smoothness, Goal Weight[0], and Goal Active[0].
  6. Enter values for the goal weight attributes. For complete information on setting goal weight attributes, see Goals.

Assign shaders to sets

If you selected sets as the post-operation option, you can assign shaders to the sets.

To assign shaders to sets

  1. Create the shaders.
  2. In the Outliner, turn on Display > Set Members.
  3. Expand the nameShatterShard# node to display the set members.
  4. Select the set members.
  5. From the Rendering menu, select Lighting/ Shading > Assign Existing Material > shadername.

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