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Birth Channel Generator Tool - Krakatoa CINEMA 4D

Last edited on April 11, 2014

Introduction

The Birth Channel Generator tool is located under the Tools tab of the Krakatoa Render Settings dialog.

It can be used to scan an existing particle file sequence and produce a new persistent channel with the initial value of an existing channel.

For example, you can produce a dedicated BirthPosition channel containing the initial position of each particle at the time of birth. It could be used for "sticky" Camera Mapping where the color of the projection is taken from the birth place of the particle even as it moves away from that point in space.

You can reprocess the output of the previous run of this tool again and again to keep on adding "Birth" channels, e.g. BirthColor, BirthTextureCoord, BirthVelocity etc. The names of these channels are completely arbitrary - use the <Custom Channel> option to enter the desired name. Remember that channel names must start with a letter, contain only letters and digits, and are typically capitalized.

Note that the tool will transform input and output data according to the scene settings. For example, if reading a BIN file sequence and saving a PRT file sequence, the BIN sequence will be turned from RealFlow space to CINEMA 4D space, and the output file will be saved to PRT v1.1 file format including Metadata describing the scene scale and CINEMA 4D coordinate system. Thus loading the resulting PRT files in Krakatoa using CINEMA 4D, 3ds Max or Maya would scale and orient them properly and will produce the same result as loading the original BIN files in a PRT Loader.

User Interface

Input File Sequence text field and button 

  • Defines the source sequence to process.
  • The sequence must contain a valid ID channel to allow the tracking of particle birth between frames.
  • The file name's frame counter will be replaced automatically for each frame. 

Output File Sequence text field and button 

  • Defines the target sequence to output the processed particles to.
  • The sequence will contain all channels of the Input File Sequence, plus the channel defined by the Output Channel controls (see below).
  • You can use the output of one run as the input of another run to add more and more "Birth channels", one at a time. 

Input Selection list and Input Channel text field 

  • The two controls define the channel in the Input File Sequence to track for birth values.
  • A standard channel name can be picked from the list.
  • When the list is set to <CustomChannel>, the Input Channel text field can be used to type in the name of any existing channel in the source sequence.
  • The channel must exist in the Input File Sequence, together with a valid ID channel.
  • The default is Position
  • Note that loading a PRT sequence saved by RealFlow might cause problems because most versions of RealFlow save the ID channel incorrectly as lower-case "id". You should use either a BIN sequence instead, or first load the PRT sequence in a PRT Loader, use a Channel Copy tag to copy "id" into "ID" and resave, then process the resaved sequence. 

Output Selection list and Output Channel text field 

  • The two controls define the name of the channel to write to in the Output File Sequence.
  • A standard channel name can be picked from the list.
  • When the list is set to <CustomChannel>, the Output Channel field can be used to enter any valid channel name (valid channel names start with a letter, can contain lower case and capital characters and digits).
  • If the specified channel exists in the Input File Sequence, it will be overwritten with the "birth" value.
  • The default is <CustomChannel> BirthPosition.

Generate Output Sequence With Additional Birth Channel button 

  • Pressing this button will start the processing of the Input File Sequence and generate the Output File Sequence.
  • If the file sequences are not defined, the button will do nothing.
  • If the source sequence does not contain the specified Input Channel or the required ID channel, an error message will be displayed and the processing will not start.
  • A Progress dialog with a Cancel button will appear and display a progress bar and a percentage.