Cross-Country Soaring 2004
User Guide 
7.4 Cumulus Clouds and CCS Thermals
CCS is not capable of determining the positions of FS’ automatically-generated cumulus clouds and is not able to create clouds itself. CCS does, however, provide two ways to have cumulus clouds aligned with CCS thermals. Each method involves the use of another freeware application. Each method also requires that CCS be run in scripted mode, as the clouds themselves must be “scripted” (i.e., they aren’t randomly generated “on the fly”).
Each of these two methods involves “scenery” clouds. They’re considered “scenery” by FS. FS add-on scenery, such as that containing clouds for use with CCS, exists in the form of files with “bgl” extensions. CCS does not directly create any clouds or BGL files. Create and manage any BGL files just as you would without using CCS. BGL files have no effect if placed in the CCS program folder.
NOTE: Due to a CCS-FS interaction limitation, the
combination of CCS thermals, BGL clouds, and wind causes thermals to be farther
upwind than expected. Click here for an explanation. For optimum thermal-cloud alignment, use calm
winds or use a high thermal lean factor and light winds.
CUMULUS!
The best cumulus cloud experience with CCS thermals comes with the use of Peter Luerken’s “CUMULUS!” program. CUMULUS! is freeware and can be downloaded from Peter’s web site (http://luerkens.homepage.t-online.de/peter/). CUMULUS! is included with CCS, so if you didn’t have it already (before installing CCS), there’s no need to download and install it separately. The version installed with CCS is a CCS-compatible version. For compatibility with CCS, you must use CUMULUS! version 3.1.6 or later. Check Peter’s web site for updated versions, which could contain other improvements (e.g., improved cloud appearance, cloud motion, smaller BGL file sizes, etc.). Any following references to CUMULUS! and its processing of an input file refer to a CCS-compatible version of CUMULUS!.
During the creation of a CCS script file (script.dat, click here for instructions on creating a script file), CCS can automatically create an input file (*.cms) for “CUMULUS!. (It doesn’t do so by default.) Compiling the CMS file with CUMULUS! will create a scenery file (*.bgl) containing 3-D, dynamic cumulus clouds that match the positions and timings of the CCS thermals in script.dat. You can optionally have CCS auto-launch CUMULUS! to compile this file for you. You can choose what to name and where to put the CMS and BGL files, if you choose to create them.
Here are some details on the CCS-created CMS file. By default 20% of thermals in script.dat will be "blue" (i.e., will have no clouds defined in the CMS file). (This percentage can be modified using the CCS Control Panel.) All CMS clouds will have the same base altitude as the "Lift Ceiling..." setting in script.dat. Each cloud's horizontal and vertical size is hard-coded to the CMS file and is determined by the size and strength of the cloud’s matching CCS thermal. Larger, stronger thermals produce wider, taller clouds.
Because the scenery file (*.bgl) created by compiling the CMS file with CUMULUS! will be quite large (typically several MB), it may be desirable to share the CMS file, not the BGL file, with other multi-player users, with each user compiling the CMS file himself (using CUMULUS!). The CMS file is designed such that this method (sharing the CMS file instead of the BGL file) will result in identical BGL files for each user. In other words, this approach will still ensure that each multi-player user has the same clouds in the same places at the same times. Click here for information on CCS Control Panel’s CUMULUS!-related settings.
Thermiek
The original option for having cumulus clouds aligned with CCS thermals was to use Max Roodveldt’s “Thermiek” program. Thermiek is freeware and can be downloaded from Max’s web site (http://www.fszwever.com). While CCS still offers this option, the CUMULUS! option is generally preferred for two reasons. First, CUMULUS! clouds have finite life spans that coincide with the life spans of their CCS “feeder” thermals. A Thermiek cloud, however, exists all day long, even when its CCS “feeder” thermal is in an “off” cycle. Second, CUMULUS! clouds are 3-D, while Thermiek clouds are 2-D. There isn’t much difference between the appearance of the two, until you’re under them. Looking up at a 2-D thermal is similar to looking up at a billboard while standing under it. Also, the visual experience of reaching cloudbase is much more realistic under a 3-D cloud than under a 2-D cloud.
A Thermiek “project” file (*.prj) can be used as an input to CCS when creating a CCS script file (script.dat). (See Scripted Mode vs. Unscripted Mode for more information.) Thermiek uses (or used) this project file to generate a scenery file (*.bgl) containing cumulus clouds. Thus, the CCS script file generated using a Thermiek project file as an input will position CCS thermals such that they align with the clouds in the Thermiek-produced scenery file. Any “blue” (i.e., cloudless) thermals in the Thermiek project file will also be blue when using CCS with the resulting script file and scenery file.
CCS applies some randomness to thermals (e.g., timings, diameters, and strengths) when using a Thermiek project file to create a CCS script file. Therefore, for an accurate multi-player experience involving Thermiek-produced clouds, you should share script.dat and the Thermiek-produced scenery file with other multi-player users. This approach is necessary to ensure that each multi-player user has the same characteristics and activity periods for each thermal.