Symbols being cropped

For some reason my symbols are being cropped off on the right hand side and the bottom. Any ideas why this is happening?

The square gif at the bottom is the original. The clip from my map is what is happening to it at normal view, about 60% and 100%. Once fully zoomed in it looks normal.

Comments

  • MonsenMonsen Administrator 🖼️ 46 images Cartographer
    edited January 2020
    This is just a limitation in how bitmaps (and screens) work.
    They both consist of pixels, and everything have to be expressed in whole pixels, they can't be fractional, one pixel is always one single color.
    So, for example, the red "border" on your symbols is four pixels wide. At 60% zoom, that is 2,4 pixels on each side, so the computer will need to make a decisions if it should be 2 or 3 pixels. Of course, the process doesn't actually look at this as a whole frame, so picking the same number on both sides is by no means given. This is especially true when the symbol is part of a larger thing, like a map, since the entire thing needs to take up a fixed amount of pixels (your screen width basically), so the resize happens for the composite collection of fills and symbols that is your map, and not any individual symbols.
    This is actually one of the areas where the four-version resolution system of CC3+ helps, because if used when you import the symbols, they are individually resized when you import them, and since at that time, it is only the symbol itself being resized, the chance of the different versions being more uniform is greater, although it is by no means a given, and it may still end up being cropped in the map anyway because it needs to be sized differently.

    I also noticed your symbol having a shadow effect on the bottom/right sides. These are additional pixels that also will be considered when resizing, and does not help in getting the frame itself uniform, but actually increases the chance that those pixels gets picked instead over the red ones, causing the visual cropping effect.

    Generally, simple symbols like these are much better made as vector symbols, these are not inherently any pixel size, and CC3+ will make the best effort to have lines of the same width be represented as the same amount of pixels on screen regardless of zoom level. This may also still fail to be perfectly uniform in some cases, but much rarer than bitmap symbols.
  • I never noticed the shading before. I made these using photoshop, I’ll have to take a look at that. Thank you for the technical breakdown of how the process works.

    Does this affect how a map may print out?
  • MonsenMonsen Administrator 🖼️ 46 images Cartographer
    Yes, but a printer have a higher resolution than a screen, which usually reduces the visibility of the problem, to the extent that it might not be visible at all.
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