Terrain Tools
COGNITO
Cognito
COGNITO
BUNDLES TUTORIALS GALLERY Carrara
Cognito is a mechanical linkages choreographer plug-in for Carrara. It provides the ability to coordinate the motion of objects as if they were connected by gears, axels, or pistons, letting you control the motion of entire chains of objects with a single set of keyframes.

Cognito supports:

Axel
This directly transfers the rotation of one object to another object.
Cam
This moves away from and back towards a shaft, depending upon the rotation of the driving shaft.
Chain
This works like gears, transferring inverse rotation by the ratio of number of teeth
Crossed Chains
This transfers rotation by ratio of teeth numbers, but does not reverse the direction of the rotation
Gears
Toothed wheels there transfer inverse rotation according to the ratio of their number of teeth.
Piston
This slides backwards and forwards, and is designed to be pushed by a pushrod.
Push Rod
This connects an offset point rotating about a shaft with a piston. One end goes around and around, the other goes in and out.
Pushrod Piston and Cylinder
These two work together are are used to simulate 'steam train' type pistons that directly drive the wheels. The piston is connected to the wheel, the cylinder pivots around a connection on the vehicles body, with the piston sliding in and out of it.
Rack
This slides backwards or forwards according to the rotation of its driving object, the number of teeth it has and the number of teeth per inch on the rack.
Radial Offset
This makes an object rotate at a fixed distance around its hot point, reacting to the driving rotation.
Rocker
This is a rotational oscillation, rotating clockwise and anti-clockwise through part of a revolution. 1 complete input revolution, modified by the tooth ratio, gives one complete rocking cycle.
Trip hammer
This is a variant of rocker that spends most of its tuning very slowly one way and a little of its time turning very quickly the other way. 1 complete input revolution, modified by the tooth rotation, gives 1 complete hammer cycle.
Worm
This moves backwards and forwards according to the rotation of the driving object, the number of teeth on the driving object and the number of teeth per inch that it has. It differs from a rack in the way it transfers rotation to other objects.

These are the fundamental building blocks that Cognito provides, and you can apply them to a variety of different objects:

  • A single object
  • A group of objects
  • A light
  • A camera

Motors and Slaves

Cognito is about constructing drive chains. All drive chains start with an object designated as a motor. This object has its rotation set through the cognito interface and changed through key framing. The rotation of the other objects is derived from the rotation of the motor. The motor is not necessarily the necessarily the part that would provide the motive force in a physical system. A large gear or axels shaft is often a good thing to use as the motor.

The objects connected to the motor are slaves, and they specify the name of the object that proceed them in the drive chain. This can be either a motor or another slave. The rotation of the slave will be determined from the rotation of the driving object and the linkage between the two objects.

For example, consider a simple chain of three gears. The first is connected to the motor and turns 300 times a second. It has, say, 12 teeth. The second gear has 60 teeth, and so will rotate at 60 revolutions a second. A small gear can be linked on its axel. This also has 12 teeth, but will only rotate at 60 rpm, as it is sharing an axel with the larger second gear. A third gear, also with 60 teeth being driven by the third gear would rotate at on fifth the speed again, in this case 12 times a second.

Setup and Execution

Cognito does it's magic by transforming and rotating the objects with Cognito modifiers and the key to this is giving Cognito a consistent starting point. When building a Cognito animation, frame 0 is reserved as Cognito's starting point and does not get calculated. The Cognito animation will begin with Frame 1.

Likewise, so that Cognito understands when it's already done it's thing, Cognito animations must be saved at Frame 0. Use the Rewind button and then the Previous Keyframe button (the left arrow next to the Create Keyframes button) on the Sequencer tray before saving a file where you use Cognito.

Data Options

The first part of Cognito is a data component that appears on the fourth properties page. This lets you define the objects basic behavior. There are two buttons. One leads to the motor settings, the second to the slave settings.

  1. Teeth is the number of teeth, spokes, or links in your Cognito object.
  2. Check Motor when this Cognito object drives the movement of other objects.
  3. Rotation specifies how far the motor turns. Change this value in key frames to animate Cognito objects.
  1. Check Slave when this Cognito object is driven by another Cognito object.
  2. Enter the Motor's in the Driver field, it is case sensitive and must be unique.
  3. Control how the slave moves by selecting the Linkage. Linkage behaviors are detailed above.
  4. Pitch/Arc specifies the conversion factor for converting radial movement into linear movement when Linkage is set on Rack or Worm. Its unit is teeth or revolutions per inch.
  5. Phase Offset controls how far ahead of the motor's rotation this slave is.

Modifier Options

The second part of Cognito is a modifier that can be added on the modifiers page. You must add the modifier for an object to be positioned by the Cognito plug-in. This modifier also lets you specify some parameters of motion that are relevant only to that object. After adding the Cognito modifier, press the Cognito Modifier button to get to the Cognito dialog.

  1. Vector controls the direction of the rotation or movement. Use the Around buttons add quick picks for each axis. For rack and worm it should point along the path of motion.
  2. Value usage changes based on the Linkage.

    Cam: Distance between inner radius (start position) and outer radius
    Radial Offset: Radius from the center of rotation (start position is at 12 o'clock)
    Pushrod & Pushrod Piston: Radius from the center of rotation of the wheel (start position is at 12 o'clock). Vector should be set to point along the pushrod.
    Pushrod Cylinder: The same as the value set on the pushrod piston.
    Piston: The distance moved on a full stoke in the direction of the vector (start position is in the middle).

How do I...

Install Cognito?

Extract and copy the files to the extensions or plugins directory.

For Carrara 8.x

On Windows it is the Carrara8\Extensions directory. If you installed Carrara to the default location, this is C:\Program Files\DAZ 3D\Carrara8\Extensions or C:\Program Files (x86)\DAZ 3D\Carrara8\Extensions.

On OS X.

  1. Open the Carrara 8 folder.
  2. Ctrl-click on the Carrara application and select Show Package Contents.
  3. In the newly opened Finder window, navigate to Contents\MacOS\Extensions.
  4. Extract the contents of the ZIP and copy them there.

For Carrara 7.2

On Windows it is the Carrara 7 Pro\Extensions directory. If you installed Carrara to the default location, this is C:\Program Files\DAZ\Carrara 7 Pro\Extensions.

On OS X.

  1. Open the Carrara 7 folder.
  2. Ctrl-click on the Carrara application and select Show Package Contents.
  3. In the newly opened Finder window, navigate to Contents\MacOS\Extensions.
  4. Extract the contents of the ZIP and copy them there.

For Carrara 6.2.1

On Windows it is the Carrara 6 Pro\Extensions directory. If you installed Carrara to the default location, this is C:\Program Files\DAZ\Carrara 6 Pro\Extensions.

On OS X.

  1. Open the Carrara 6 folder.
  2. Ctrl-click on the Carrara application and select Show Package Contents.
  3. In the newly opened Finder window, navigate to Contents\MacOS\Extensions.
  4. Extract the contents of the ZIP and copy them there.

Enter my serial number?

After purchasing Cognito you will be emailed a serial number. If you open a scene with Cognito or use Cognito in a scene, the Enter Serial Number window will display. Enter your serial number in the field provided and click OK to continue.

Tips and Tricks

In the real world, gears have to be carefully shaped and all the parts of the drive chain need to be carefully assembled, positioned and lubricated. Carrara is a virtual environment and your aim is to make animations efficiently, not to be a virtual engineer. When using Cognito, remember the following:

  1. It doesn't matter what shape on object is it can still be part of a drive chain.
  2. Objects do not have to be in contact for a power transfer to occur.
  3. Silly gearing ratios - 3000:1 - work perfectly.
  4. Apply one motion to an object, put it in a group and apply another to the group. It'll work in Carrara.
  5. You need to attach the Carrara modifier to get motion, but passive parts can still be in the drive chain.

Evaluation Mode

Cognito supports an evaluation mode which allows you to try out Cognito before purchasing it. When the Cognito Enter Serial Number window is displayed, just click Cancel to go into evaluation mode. During evaluation mode, Cognito will only allow a single level of linkage, and only the Gear linkage will be available.

Release Notes

June 08, 2010

  1. Changed where serial numbers are saved to a more modern OS friendly location. This fixes a problem with saving serial numbers on the 64-bit Windows Carrara when UAC is turned on.

Pricing

$29.95 US dollars for a single user license. The single user license includes the right to use the product with up to 5 render nodes using Carrara 6.0 Pro or better. Pricing is also available for a render node site license for use with Grid.

Ordering

Place your order online for Carrara using our secure server. Use the same link for PayPal, credit cards by fax or phone, and checks.

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