PenPal

MaxScript Release 0.50 Beta (10/08/2003)

Copyright (c) 1998-2003 by Borislav Petrov, Bobo's Rendert**ls. 

SHORT DESCRIPTION

PenPal is an Animation Painting utility.
It lets you simulate effects like pen writing, brush painting, spray coloring, water wakes and more...
It creates an animated texture based on the relative motion of two objects.

HOW DOES IT WORK?

PenPal compares the distance between the pivot points of two objects ("Paper" and "Pen") in Paper's object space and draws a trail along the animation trajectory. A single bitmap is written for each frame, and the resulting animation is applied as IFL animated texture to the Paper object. The Z-coordinate distance can be used to control the Pen Up and Down state.

SOME EXAMPLES

  • Carving into Stone (PenPal b&w Mask for Bump Map Letter)
  • Burning Metal with Laser (PenPal Bump Map)
  • Wheel Track (PenPal Bump Map)
  • Color Stamps (Animated Ink)


    • FEATURES

    Beta 0.5 (10/08/2003)
    This version should run in MAX 4, 5 and 6, but will NOT run in prior versions.
    It was a quick job editing the code and there might be still features that do not work as expected.

    Beta 0.46 (7/28/98)
    This version fixes a severe bug in the Slash Pen inheritant to the switch to Rollouts in Version 0.45
    An additional check for MAX 3.0 version is performed and an additional message is displayed.
    PenPal passed the tests for MAX 3 compatibility. If you find any troubles when running in R3, please email me!

    Beta 0.452 (6/26/98)

  • After the panic caused by the bug, I had enough time to fix it the right way...

    • Beta 0.452 will automatically detect the MAXScript version used and switch PenPal to the right color multiplication mode. I will leave the manual switched 0.451 for download in case you want to have control over the bug :o)

    Beta 0.451 (6/25/98)

  • A bug fix in MAXScript for R2.5 caused bug in PenPal! :o(

    • Beta 0.451 adds a checkbox which will let you select the MAX release you are using prior starting PenPal texture generation. Using the wrong version settings will cause wrong ink colors!
    MORE ABOUT THE BUG: In MAX R2, there was a bug when multiplying a color value and a float between 0 and 1. Instead of floats, one had to use values in the range 0-255. This has been fixed in R2.5, and causes PenPal to generate color values too high to be correct. The new compatibility checkbox selects which range to be used - [0..1] or [0..255].

    Beta 0.45 (2/25/98)

  • Replaced the UI Groups with Rollouts.
  • Added a new Random Seed value that lets you change the Spray appearance.
  • Replaced the "Random Spray Dots" button with a dropdown list with 3 options:
  • Added support for Movies as Custom Brushes. You can load any AVI, FLC or IFL file to be used as a custom brush. An additional field "Brush Frame" will let you animate the brush in any way you like - it uses a Linear_Float controller in TrackView to control which brush frame is shown on which scene frame. When selecting a file with more than 1 frames, you will be prompted to create keys in the current animation segment that let the animation play from start to end.

    • PenPal will check the size on frame 1 only, so if the brush changes its size over time, some frames might become cropped.
    TIP:An easy way to create animated custom brushes is creating a shape in MAX, adding an extrude modifier and material, and animating some parameters. Render the shape to FLC or AVI and... voila!
    NOTE that you should use a lossless CODEC like RLE or similar for your AVI Brushes in order to get clean background color. Or you can use FLC instead.
  • Added a new option that controls the form of the Fade Out Scale trail. You can select from the dropdown list among these presets:
    • [Fade Out Scale Types Example]
    NOTE that these settings apply to the Fade Out Scale only. The Color Fade Out will be always Linear. This is because in the case of Square and Sine Fade the "oldest" brush stroke gets almost pure background color as the fade out value comes close to 0.
  • Added a (very slow!) option for Recursive writing over exisitng PenPal textures. Whan activated, this function loads the previously rendered texture frame first and applies the actual PenPal brush over it. This way you can lay multiple brushes and sprays over the same texture, or have two different brushes on the same texture (like in example "Baby's First Steps" - originally I used 2 different textures for the left and right footsteps.)

    • Please keep in mind this option uses the same code as the fade out, but always starts redrawing from frame 0, so it progressively slows down... I included the option because it was "for free" since the fade out code was already there, and all I had to do was adding a new button...
    You should consider compositing or mixing separate textures in most cases instead. 

    Beta 0.42 (1/31/98)

  • Added a new checkbox that can turn off the automatic adjustment of the Pen Up values when picking a new Pen Object.
  • Added a new checkbutton that can turn off automatic assignement of materials to the Paper Object. Turn this off when you have adjusted a complex texture including a PenPal IFL, and just want to rerender the texture.
  • Fixed some bugs in the Custom Brush Fade Out Scaling code that crashed PenPal sometimes.
  • Created the Samples above... take a look at them! I might write some tutorials on how to create these effects later. 


    • Beta 0.41 (1/31/98)


     
     

  • Paper Object selection

    • To start working with PenPal, select the Paper Object first. In this version, the Paper Object should be a Box, Flat Patch or a Flat Mesh with Planar UVWmap.
    In future versions, there will be support for more object topologies and UVW settings like Sphere, Cylinder etc.
    The Paper Object may be freely oriented in World Space. Because the Paper's local coordinates and orientation are used, you should animate the pen in the Paper's object space - in the Transformation Manager, select "Pick" from the dropdown list and select the paper. Then press "Animate" and set the pen animation.
  • Pen Object selection

    • This option is activated after a Paper Object is selected. The Pen Object can be ANY animated object incl. Primitives, Lights, Helpers, Particle Systems etc. If the object itself has no animation keys, and the Paper Object isn't animated either, you will be prompted to make sure the Pen has animated parents. You can have any hierarchy of objects to simulate pen motion, pen up and down etc. After the object is selected, its "Show Trajectory " checkbox will be automatically activated.
  • The WRITE! button becomes active after both Paper and Pen Objects have been selected.

    • You can press it again everytime you have changed pen or paper settings to generate a new version of the texture.


     
     

  • Path and File settings

    • PenPal generates a sequence of Bitmaps and a single IFL file that lists them to be used as an animation. The supported bitmap formats are JPG, TGA, PNG and BMP. More might be implemented in the future. IFL gives you more flexibility to mix frames from different animations, reverse the animation or change speed etc. You can use EZlist(tm) to do this.
    You can set the path the images are written to, and the prefix to be used for both IFL and Bitmaps. By default, the path is a PENPAL subdirectory of the directory the MAX scene has been loaded from. Be careful if you load the scene AFTER starting PenPal. You should set the save directory by hand or restart PenPal.
    You SHOULD set a valid path before creating a texture!
    You can enter your own path, or use the "Get Animation Path" button to set an existing one.
    The default Prefix for both Bitmaps and IFL is "penpal".
    You can turn off writing to disk to just preview your settings.
    You can turn IFL creation off in case you want to use your own IFL created with another program like EZlist(tm) or MAX IFL Manager.
    By default, the resulting bitmaps will be previewed in a VFB, but you can turn this option off.
    NOTE:The absolute path to the IFL will be included in the Bitmap Map so you don't have to include it in the MAX Paths settings.
  • Paper Color settings - lets you set the background color for your writing.

    • NOTE:The Bitmaps have no Alpha channel. If you want to Mask the Texture with other maps in the material, you can use a pure black or pure white background color and apply it as both Mask and Map bitmap... A Generate Alpha function might be implemented later.


     
     

  • Paper Size settings

    • After selecting an object, PenPal checks the Bounding Box' Width and Height of the object (local X and Y coordinates) to define a texture that fits the Paper.
    By default, there will be one pixel/unit, which means that an object that is 800x600 units in X/Y directions will generate a sequence of 800x600 resolution Bitmaps. You can change the number of pixels per unit using the Dots Per Unit field.
    VERY IMPORTANT is to know that the Brush Size settings are applied as ABSOLUTE values, so changing the Dots Per Unit value will effectively scale the Brush relatively to the Paper Object.

     NOTE:In the current version, PenPal will NOT add an UVWmap modifier to the object. Most objects in MAX will activate their coordinates automatically. In certain cases (see "Known Bugs and Limitations") you might want to set up your own UVWmap modifier and adjust the Paper Size to fit the UVWmap size. In future versions there might be an automatic function for this...


     
     

  • Pen Colors:

    • There are two color picker fields for the pen color. By default, the first (Ink) will be used for Procedural brushes, Custom brushes will retain their original colors except the background. You can press the [Use Ink] to replace all non-background colors of a Custom Brush with the Ink color. The second (Mix) color becomes available when the [Spray] option is activated. Press [Use Mix] to get a random color between the two colors in the spray.
    Both Ink and Mix are animatable - you can press Animate and adjust the colors over time. The dafault Controller Type is Bezier_Point3, but you can use TrackView to change it and to adjust the animation.
    NOTE that there will be no red brackets around animated values in PenPal.
  • Brush Preview window:

    • Renders a single brush shape based on the current Pen settings.
  • Play Animation button

    • The Preview Window will not update automatically when you play the scene animation. To preview any animation settings to the brush, press the Play button. It will play from the current Time Slider position to the end of the current animation segment.
  • Use the Update button to refresh the Preview with the actual settings after you change the current scene time using the time slider. The number to the right will show the currently displayed frame.
  • Get Custom Brush lets you select Bitmap file to use as Brush. The color of the top left corner will become transparent to show the Paper color. If the extents of the non-background colored part are higher than 120x120, the bitmap will be cropped.
  • The dropdown list will let you select from the currently implemented Brush Shapes: Rectangle, Ellipse, Slash and Custom.

    • The animated values of the Bush use a Linear_Float controller. You can change it to any controller type you want using TrackView.
  • Press the [Lock] button to lock Width and Height values together.
  • With Rectangle and Ellipse, both values can range from 1 to 90.
  • With Custom , both values can range from 1 to 120.
  • The Slash shape lets you go with the Width settings from -90 to 90.
  • An additional Thickness field becomes available for the Slash settings. It can range from 1 to 40.
  • The [Spray] button lets you fill the brush shape with random dots. The relation between number of ink and paper dots is controlled by the [Spray Coverage] value. PenPal will generate random numbers between 0 and the Coverage value and draw an ink dot when the result is 1. The default of 1 gives a coverage of about 50%. The max. value of 100 means about 1% ink and 99% paper color. To use random dot matrix for the Spray, leave the [Random Spray Dots] checked. If you uncheck it, the matrix will remain fixed along the animation.
  • The [Brush Overlay] button is active by default when Spray is activated, and when a Custom Brush is selected. In this case, the samples are added together. Slow motion results in darker regions, fast motion in brighter regions.

    • [Spray: Overlay On], [Custom Brush: Overlay On]
    If unchecked, the samples will cover each-other, resulting in a regular look without darker and brighter regions.
    [Spray: Overlay Off], [Custom Brush: Overlay On]
    NOTE that the default Overlay mode is MUCH SLOWER, but is more useful for Spray simulations.
  • The Pen Subsamples field defines how many times a brush will be calculated between two frames. Higher values will slow down the utility, but will yield more fine results.
  • The Texture Blur field is the Blur Value to be set in the Bitmap Map.

    • [Sample: Blur 5.0], [Sample: Blur 1.0].
    Blur is NOT rendered and saved with the BMPs, but is just a parameter of the material, so you can adjust it anytime in the Material Editor instead of rendering the whole texture again.
  • The [Use Pen Up] button is active by default. PenPal monitors the relative Z position of the Pen to the Paper Object. When the Z distance is higher than the Pen Up value, no texture is drawn.

    • [Sample: Pen Up On], [Sample: Pen Up Off]
  • When the [Pressure Ramp] button is checked, both Pen Up and Pen Down values are used. A pressure value is calculated based on the pen position between these values, and the ink color is mixed with the paper color according to the pressure percent. Values bellow Pen Down will paint with 100% ink, values above "Pen Up" will not draw at all.

    • [Sample: Ramp On]
    NOTE:The Pen Up and Pen Down values are set automatically when the Pen Object is selected. The Pen Down value will equal to the lowest Z distance of the Pen Object from the Paper's Pivot point, the Pen Up value will be 1 unit higher than the highest Z distance in the animation. Don't forget to check and adjust these values after picking a new Pen Object.

    TIP:If you want to simulate different pressures while writing, you can create a pen that moves along the XY plane without going up in Z, and link a Dummy that will follow the pen and have its own animation in Z direction. Select the Dummy as the Pen Object and set the Pen Up value to be lower than the highest Z value of the Dummy. This way you will be able to control the pressure of the pen without really taking it up from the paper.
    [Sample: Pen Up lower than highest Z], [Sample: Pen Up higher than highest Z]

  • The new Fade Out functionality lets you create trails that disappear over time. In addition, the older brush trails can be scaled over time. These functions lets you create bump maps for water wakes a la Splash Max.

    • NOTE that the Fade Out function will slow down generation time significantly!
  • The Fade Out Time field is used to set the Life of the brush strokes. After this number of frames, the trail disappears completely.
  • The Fade Brush Scale defines the scaling of the brush over time. The default value of 1 means no scale at all, values from 0 to 1 will scale down, from 1 to 10 will scale up.
  • The [Fade Out] button is unchecked by default, you have to activate it to use the new fade out functions.


    • KNOWN BUGS AND LIMITATIONS

  • MAXScript cannot set pixels beyond the left and rigth bitmap borders. This means that even when a small part of the Brush shape tries to write outside of the Bitmap, there will be no ink at all.

    • THERE IS A WORKAROUND: You can add a UVWmap modifier manually, set its Lenght and Width higher than the paper's size, and enter the same values for the Paper Width and Height. This will let PenPal write a wider texture that goes beyond the edges of the paper.
    [PROBLEM:Animation wider than Paper], [SOLUTION:UVWmap wider than Paper]

    DOWNLOAD PENPAL BETA

    Beta 0.50 for Max 4, 5 and 6

    Beta 0.46 Encrypted for Max 2, 2.5 and 3.x