Open Inventor - Engines

and the Workshop ----on Jul. 17th & 18th.

Engines

• You want to animate your Open Inventor objects.
• You want to establish one part of your objects connections with some other parts of your objects.

Structure of Engines

Types of Engines & Their Fields

1. Arithmetic engines
   • SoCalculator
   • SoBoolOperation
   • SoInterpolateFloat, SoInterpolateRotation, SoInterpolateVec2f, SoInterpolateVec3f, SoInterpolateVec4f
   • SoTransformVec3f
   • SoComposeVec2f, SoDecomposeVec2f, SoComposeVec3f, SoDecomposeVec3f, SoComposeVec4f, SoDecomposeVec4f, SoComposeRotaion, SoDecomposeRotaion, SoComposeMatrix, SoDecomposeMatrix
   • SoComputeBoundingBox
2. Animation engines
   • SoElapsedTime
   • SoOneShot
   • SoTimeCounter
3. Triggered engines
   • SoCounter
   • SoOnOff
   • SoTriggerAny
   • SoGate
4. Engines used for array mannipulation
   • SoSelectOne
   • SoConcatenate

Animation Engines

Elapled-Time Engine

Inputs
• SoSFTime timeIn (For running time)
• SoSFFloat speed (For speed)
• SoSFBool on (When it is TRUE, it starts runnning. When it is FALSE, it stops.)
• SoSFBool pause (When it is TRUE, it stops temporarily. When it is FALSE, it continues running.)
• SoSFTrigger reset (For resetting)

  Outputs

• SoSFTime timeOut (Elapsed or changed time)

One-Shot Engine

Inputs
• SoSFTime timeIn (For running time)
• SoSFTime duration (For duration)
• SoSFTrigger trigger (To start the cycle)
• SoSFBitMask flags (To control flags)
• SoSFBool disable (When it is TRUE, the timer is disabled.)

  Outputs

• SoSFTime timeOut (Elapsed time)
• SoSFBool isActive (When the cycle is active, it is TRUE.)
• SoSFFloat ramp (A float value from 0.0 (when the trigger starts) to 1.0 (when the duration is reached))

Time-Counter Engine

Inputs
• SoSFTime timeIn (For running time)
• SoSFShort min (For the minimum value of the counter)
• SoSFShort max (For the maximum value of the counter)
• SoSFShort step (For the step value of the counter)
• SoSFBool on (When it is FALSE, the conter pauses.)
• SoSFFloat frequency (For number of the circle related to min and max)
• SoSFFloat duty (For the value of the duty circle)
• SoSFShort reset (To reset the counter)
• SoSFTrigger syncIn (To restart at the first point of the cycle)

  Outputs

• SoSFShort output (To count min and max)
• SoSFTrigger syncOut (To trigger at the first point of the cycle)

Samples of Animation Engines

• First, this is a draft without engines. (source file)
• Sample 1 with Animation Engine. (source file) It uses an Elapled-Time Engine.
  You can use this Makefile if you want to compile all of sample files. Please command "smake." (NOTICE: The place where libraries exist may be changed.)

  Explanation ; The timeOut output of the Elapsed-Time Engine (myConter2) is connected a SoRotationXYZ field (myRotXYZ2). This field inserts the timeOut value into Z slot of a vector.

  

Gate Engine

Inputs
• SoSFBool enable (It enables to continue passing through.)
• SoSFTrigger trigger (To copy one value)
• input (When the gate is open, this value is copied to the output.)

  Outputs

• output (When the gate is open, this value includes a copy from input.)

Samples of Gate Engine

• Sample 2 (binary file) with a Gate Engine. (source file) Please save the file, and execute it. (Don't forget to change permission.)
• Sample 3 (binary file) with a Gate Engine and path. (source file) Please save the file, and execute it. (Don't forget to change permission.)
  You can use this Makefile same as the above thing.

  Explanation ; In this case, this sample connects each of Elapsed-Time Engines (myCounter and myCounter2) to each of Gate Engines (gatecube and gatecone).
  • In case of Sample 2, pressing the left mouce button enables and disables the gate engine (gatecube) and pressing the middle mouce button enables and disables the gate engine (gatecone). Each of Gate Engines controls the movement each of red a cube and a blue cone.
  • In case of Sample 3, pressing the mouce button on the red cube enables and disables the gate engine (gatecube) and pressing the mouce button on the blue cone enables and disables the gate engine (gatecone). Each of Gate Engines controls the movement each of red a cube and a blue cone.
  • A difference between sample 2 and sample 3 is each of callbacks.
  

Arithmetic Engines

Boolean Engine

Inputs
• SoMFBool a (First argument to the Boolean operation)
• SoMFBool b (Second argument to the Boolean operation)
• SoMFEnum operation (The Boolean operation)

  Outputs

• SoMFBool output (Result of the Boolean operation by inputs)
• SoMFBool inverse (Inverse of output)

Calculator Engine

Inputs
• SoMFFloat a, b, c, d, e, f, g, h (These inputs are the floating point values.)
• SoMFVec3f A, B, C, D, E, F, G, H (These inputs are the vectors.)
• SoMFString expression (The expression to be estimated)

  Outputs

• SoMFFloat oa, ob, oc, od (These outputs are the floating point values.)
• SoMFVec3f oA, oB, oC, oD (These outputs are the vectors.)

Other Samples

• KeyAnimation is an example using keyboard actions. It uses a Calculator Engine, a Compose Engine, and a One-Shot Engine. (by Prof. Herder)
• This sample file includes 3 letters going round a chair. (They play musical chairs, and the letter S is always a winner.) Here is an iv file.