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Brush Dynamics

The method through which Studio580’s brush tool forms strokes in response to mouse movements is both limiting and problematic. It is limiting in that it can simulate the stroke behavior of only a single kind of artist’s brush—a flat. And it is problematic in that it performs no smoothing of the captured brush trajectory. This can lead to the formation of kinks and other visible first-order discontinuities when the mouse is moved too quickly or when its trajectory changes direction too rapidly. In a near-term future version of Studio580, this simple stroke capture system will be replaced with a far more sophisticated one that smoothes the captured mouse trajectory (such as through a spline interpolation scheme) before using it to generate the stroke body. This improvement is discussed on the Future Directions page. Unlike solving the smoothing problem, adding more brush behaviors to Studio580 is a longer-term project, not a near-term one.

Nevertheless, the Studio580 brush tool is perfectly usable as-is, though it can sometimes be vexing. For more information about mitigating the problems of the brush tool and getting the most out of it, see the Tips & Tricks Guide.

Synthesis and Decal Run Artifacts

The texture synthesis scheme that Studio580 uses to generate the surface textures of brush strokes employs pseudo-randomness and noise. Occasionally, a stroke containing one or more trace visual artifacts (such as a single off-color pixel) may be generated. Other times, a stroke may be a generated that appears out-of-place with respect to its surrounding strokes, even though all were made with the same brush. At other times still, the terminal end of a stroke may appear incorrectly colored (this is due to a known bug in the way that Studio580 calculates the length of decal runs, or the chunks of texture information that are the units of synthesis).

If any of these problems do occur however, they’re very easy to solve—just undo the bad stroke and draw it again. Since all of the problems discussed in this section are very rare, they probably won’t affect the next stroke you draw.

Deleting Brushes and Brush Support Files

Every brush in Studio580 depends on two files on disk—a source image file, and a similarity map file (the roles of these two files are discussed at length in the Brush Creation Guide). While each brush can only be linked to one source image file and one similarity map file at a time, several brushes can be linked simultaneously to a single source image or similarity map file. Thus, it is possible for many Studio580 brush objects to depend on the same file or files.

While this arrangement is convenient, it does complicate the process of deleting brushes. In general, completely removing a brush from your system comprises two tasks. First, you must delete the brush object from Studio580. You do this by selecting the brush in the brush list at the left of the Brush Options dialog box and then clicking the “Delete” button that appears just below the brush list. While this removes the brush from Studio580, it does not remove the underlying source image and similarity map files that support the brush from your disk. You must remove these manually, via Windows Explorer.

A problem occurs however, if you delete these files on disk while another brush object is still linked to them. Because multiple brushes can link to same file, as discussed above, this is a possibility. When you select a brush object for use in Studio580, it dynamically loads its support files—its source image and similarity map—from disk. If a brush object tries to open a support file that doesn’t exist, Studio580 will crash. Furthermore, if you delete or move support files used by the currently selected brush, such that Studio580 cannot access them, Studio580 will crash on startup the next time that it is launched.

In future releases, Studio580 will handle “brush support file not found” errors of this type in a more effective way than just crashing, likely by displaying a message box notifying the user of the problem and then removing the affected brush from the brush list. Indeed, improved error handling is set forth as a desirable near-term improvement on the Future Directions page.

Until these improvements are made, you can avoid crashes due to brush support file not found errors through these simple guidelines:

Keep all brush support files in your User folder—if you keep them here, you’ll never need to move them anywhere else, so there’s no chance that Studio580 will try to find them in one location after you’ve moved them somewhere else. See the Quick Tour for a discussion of the directory structure of the Studio580 distribution.

Only delete support files when you’re sure no brushes use them—or better yet, don’t delete them at all. Brush support files are small, and modern hard disks are huge, so why bother deleting them anyway?