Changing terrain of sections of coastline landmass
Brian Stormont
Newcomer
What is the best way to go about changing areas of a landmass to different colors when they involve coastlines? For example, I have a map that was created via a contour of a bitmap, so it is one continuous landmass polygon. If I want to make a section of it a different color, and have it follow the coastline exactly, what would be the easiest way to do that?
Here is an example of part of my map:
In this map, the land that is white is one single polygon. I wanted to start shading different sections different colors to represent terrain differences, but I'm stumped at how to get that shading go right up to the edge of the coastline.
One way I thought of would be to split the path that makes up the polygon of the land, draw a new path where I want to have the land shaded a different color, join that path with the piece of the coast I split, and then convert that joined path into a polygon. That works, but then the rest of the landmass is no longer a polygon, so I have make a copy of the outline of the shaded area I just created so I can join that to the original land mass coastline to make it a polygon again. That's very tedious. I figure I must be missing some other more simple way to do it.
The blue sea color is drawn first, and the land sheet is just drawn on top of a giant blue box, so I can't draw rough-shaped polygons for the terrain colors and go outside the edge of coast and let the sea hide the edges - I need to follow the coastline exactly.
Thanks for any ideas.
Cheers,
Brian
Best Answers
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Maidhc O Casain
🖼️ 11 images Surveyor
For coloring different areas, I copy the landmass to a different sheet, split it in all the places I want and make separate polys on THAT sheet for coloring. I usually leave the original underneath (higher up in the sheet list) for "non-destructability" and - if the original does have a color or texture - I put a transparency or a blend on the colors.
This is what I did for Insulae Britannia. Here's a link to that map in my gallery if you want to see to be results:
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Loopysue
ProFantasy 🖼️ 41 images Cartographer
About the length of time it takes to redraw - it might be the same or even worse after you split the polygon. What's causing the speed to drop is having to redraw millions of nodes every time you pan or zoom just a small amount.
You could use SIMPLIFY to remove all nodes that are less than the specified distance apart, and enter a value like 1 to start with when prompted. If this simplifies the outline too much undo it and try again with a decimal fraction of 1. Even if you use zero it will remove any nodes that are right on top of one another. You might be surprised by how far you can go with it.
SIMPLIFY works immediately on whichever polygon you pick. There's no "Do It" required.
Answers
I figured out a simpler way - using the trace option when drawing the new landmass. I hadn't realized that it was possible to do the tracing for a subset of the points for the new polygon. I should always read the full text of the cursor text when I'm using CC3+. :-D
Given my landmass polygon is so large, I need to temporarily split it into smaller segments, otherwise CC3+ takes a verrrry long time to refresh as it tries to parse all the nodes of my continent's landmass polygon for every mouse movement I make. But, making two temporary splits is still a much faster process than what I was originally trying to do.
Is there something even simpler than this second approach?
For coloring different areas, I copy the landmass to a different sheet, split it in all the places I want and make separate polys on THAT sheet for coloring. I usually leave the original underneath (higher up in the sheet list) for "non-destructability" and - if the original does have a color or texture - I put a transparency or a blend on the colors.
This is what I did for Insulae Britannia. Here's a link to that map in my gallery if you want to see to be results:
https://forum.profantasy.com/galleryviewer/36/35607
About the length of time it takes to redraw - it might be the same or even worse after you split the polygon. What's causing the speed to drop is having to redraw millions of nodes every time you pan or zoom just a small amount.
You could use SIMPLIFY to remove all nodes that are less than the specified distance apart, and enter a value like 1 to start with when prompted. If this simplifies the outline too much undo it and try again with a decimal fraction of 1. Even if you use zero it will remove any nodes that are right on top of one another. You might be surprised by how far you can go with it.
SIMPLIFY works immediately on whichever polygon you pick. There's no "Do It" required.
Thank you both for the helpful tips.
I hadn't thought of making a copy of the landmass to a different sheet and split things there. That's a simpler process not having to rejoin the split pieces later.
Also, using SIMPLIFY on my coastline did dramatically speed up the trace drawing.
Cheers,
Brian