Smooth path drawing artifacts

Hi,

I'm new to cc3+ and am trying to draw a labyrinth. I used the smooth path tool to draw the complicated curve, and then tried (using several methods) to give the line thickness (change line width, change pen thickness, change like draw tool to make it into a river, etc). No matter what I do, the curve just looks like a mess (I'm a programmer, and guess that it is some kind of winding rule issue when filling). As I zoom in and out, different sized triangles flicker in and out of existence or bars of color cross over the lines inverting them. I've attached an image demonstrating the problem.

Drawing a curve seems like a super basic operation, so I'm distressed that I ran into this kind of issue so quickly :(

Thanks in advance for your help!

Comments

  • You crossed over the different lines. That is what it looks like to me.
  • MonsenMonsen Administrator 🖼️ 46 images Cartographer
    edited July 2020
    Did you happen to place some nodes very close to each other? When nodes gets too close, it can cause some weirdness with thick lines. Don't think I've seen as much issues as you seem to have accumulated here though.

    If so, you can probably get rid of some of the nodes with the simplify command. (just type SIMPLIFY on the CC3+ command line) I don't know the scale of your map, so it is difficult to recommend a simplification distance, but try with a distance that is about a quarter of the radius of those curves and see if that helps. (You can measure distance in the map by using Info -> Distance)

    You can also use the Info -> List command on your paths, you can then examine the node list for close nodes.

    If you post the .fcw I might have a look at it for further analysis.
  • Thanks for the quick replies! I've attached the file, and am playing around with simplify. Using a distance of .002 seems to fix the drawing artifacts, but also leaves it all straight line segments rather than smooth curves. Note that the artifacts don't always show, but if I zoom in and out they appear and move around depending on zoom level. Increasing the line width also makes the artifacts worse.
  • MonsenMonsen Administrator 🖼️ 46 images Cartographer
    Looks like you have encountered a precision error.

    I noticed your map was really small, only 2 by 2 map units. Nothing wrong with that in itself, and normally not a problem either, but it seems like making such a winding shape on such a small map did cause some issues.

    So, the workaround I recommend here is to multiply the map size by 100, that seems to work much better.
    To rescale the entire map, right click the Scale imagebutton, choose non-visual scale. When prompted to select entities, simply hit the a key for all, then d for do it, and type in 100 for the scale factor and 0,0 for the scale origin.

    After doing this, you also need to change the default symbol scale in Drawing Properties image to make sure CC3+ suggests the right size for new symbols the next time you load the map, and you'll also need to change the scale of the fills in the fill style dialog.

    If you don't want to mess with all the fill scaling, you can also scale this map, then start a new map in the new size (should be 200 by 200), and then copy the entities over from this map using clipboard copy.


    Normally, I wouldn't recommend this, because I am a firm believer in keeping the map scale correct, so if you are mapping a 2 mile by 2 mile area, the size should be 2 by 2, but in some cases, a workaround like this may be required.


    Note that the path in the file you sent me was straight. You can always convert that back to a proper smooth path using the Straight to Smooth command (right click Explode image).

    Hope this helps
  • Thanks! Away from my computer for a bit, but will try your suggestions. I appreciate the thorough investigation and answers.
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