Ice Shelf creates a flat area around the shoreline and over any areas of the underwater terrain that rise to within the shelf limit. It can also apply an effect that looks like thinner areas of ice and pools to the shelf area. Ice Shelf is still a bit of a novelty plugin at the moment, it isn't really as practical as Euphotica or Sorta Surf, but it can still give an interesting effect. I hope to make it more useful in the future.

Click for larger image

The Interface

Mac version	Windows version

Ice Shelf is easy to use. Here's a guide to it's settings :

• File Menu
  The File menu allows you to open and save your plugin settings. The settings are saved in files with a .wwk extension. All of the different plugins save their settings in files with a .wwk extension, but each has it's own format. If you try and open a .wwk file that was saved by a different plugin, then you will be notified about it.
  

  All of the commands in the File menu should work pretty much as you expect them to, however there is a File Menu page here if you would like it explained.
  

  WaterWorks settings files are cross platform, and can be exchanged between the Mac and Windows versions.
  

  Please note that mask information is not currently saved in the settings file.
  

• Shelf Limit
  This setting controls the depth that the ice shelf extends to. Any area of the water where the depth is between 0 and the shelf limit will have the ice shelf effect applied. Note that this doesn't just mean the shoreline, but any area where the depth is shallower than than the shelf limit. For example, if there was a piece of terrain offshore that was completely underwater, but which rose so that the shelf limit was less then the breaking depth, then you would get an area of ice. Note that the units used for this setting are Terragen units, not metres.
  

• Patchiness
  This setting controls the patchiness of the ice surface. It creates an effect that looks a little like meltwater standing on the surface. Values can range from 0 to 100, with 100 being the greatest amount of patchiness.
  

• Ice Colour
  Clicking the Colour button brings up the colour picker, which lets you choose the colour of the ice.
  

• Patchy Colour
  Clicking the Colour button brings up the colour picker, which lets you choose the colour of the patchy areas.
  

• Use Mask checkbox
  This check box allows you to choose whether or not to use a mask to control where the ice effect appears. You can generate masks using the Mask Generator plugin.

• Mask Settings button
  Clicking on this button will bring up the Mask Settings dialog box, which allows you to select a mask file to use. See the Mask Settings page for more information.

• Cancel button
  This button closes the plugin window without recording the changes you've made to the settings.

• OK button
  This button closes the plugin window and records the changes you've made to the settings.

How Ice Shelf interprets masks

When reading a mask loaded from a file, if Ice Shelf encounters a black pixel, then the ice effect is not applied. If Ice Shelf encounters a white pixel, or any other colour, the effect is applied. If, for example, you wanted to put a crack in the ice, you would draw on the mask in black, and when it came time to render, the water would show through instead of ice in that area. Bear in mind that the ice effect is still constrained by the Shelf Limit setting. You do not need to colour the entire water area of the mask in black. To get an indication of the extents of the ice effect, you can set the Depth Contour setting of the Mask Generator to the same value as the Shelf Limit, and the area the ice effect covers will be drawn in grey on the mask.

Tips for using Ice Shelf

Here are some hints and tips to help you get the most out of Ice Shelf :

• Ice Shelf flattens out areas of the water that the ice covers, so you if you want to preserve this, you shouldn't place any other plugins that might modify the geometry of the water over the top, in other words, below it on the list. An example of a plugin that modifies the geometry is Height Ripples Example.
• If you find you have a stray piece of ice where you don't want it, you can use Terragen's sculpting tools to lower the terrain in the area. If you lower it so that the water above it is deeper than the shelf limit, the ice won't show up anymore.
• For much finer control over where the ice effect appears, you can use the Mask Generator plugin to create a mask which you can edit in a paint program ( such as Photoshop, Paint Shop Pro or GraphicConverter ). For example, you can make a complex network of ice flows and leads by scribbling on a mask. Ever wanted to write your name across the Antarctic ice shelf ? Now's your chance...
• Looking at pictures of real ice shelves, it seems a lot of the time the standing water on the surface, whether it be from meltwater or rain, looks grey and not bluey or greeny, as perhaps you might imagine. After all, the water standing on the surface isn't really deep enough to take on a what you might usually suppose to be a "watery" colour.

Future Ice Shelf developments

There are several future improvements that I have in mind for Ice Shelf. One thing I'm likely to add will be control over the bumpiness of the ice. At present the ice is perfectly flat and doesn't have much detail. A lot of the time the ice would have snow on it, and hardly anything is ever perfectly flat. I'll probably allow control over the distribution of the bumpy areas, so that you can have some parts of the ice bumpy, and some parts smooth.

Requirements

WaterWorks needs the TGPGuiLib to run. This file provides cross platform interface functionality. To find out more about the TGPGuiLib and download the latest version, visit it's website.

© Jo Meder 2000, all rights reserved