Brush Settings When Stroking Path

[sallyanne]

Wouldn't the dynamic 'track direction' help with this? Just have to work out what your spacing would need to be.

[Ofnuts]

(10-11-2022, 11:55 AM)sallyanne Wrote: Wouldn't the dynamic 'track direction' help with this? Just have to work out what your spacing would need to be.

It's obviously already set...

[rickk]

I have concluded that the real problem here, was "kid in the candy store" mentality.  I wanted to believe that I could save a brush that would FOREVER serve any need I might have to ever again draw a rail line.

It's fun to ponder that Gimp can shelter us from having to admit we have little actual talent, and in more ways than not, it often succeeds.   But in some instances reality comes clearly into focus.

Perhaps  in 20 years, I get to where I would like to be.

The real exercise here  is that I need to become more proficient in plotting parallel paths. When you get to a line with a radius, simply moving the previous path don't cut it. Using the "grid" tool has helped me a lot the last couple days. Perhaps with practice!!  


I think this one required 4 paths



And this one required 2. (I was surprised by the re-emergence of aliasing when I applied  the gradient., the foundation line was as smooth as a roller coaster)



At this point I'm just pleased to have progressed to the point I have, compared to one week ago. Thanks to all your help 

[Ofnuts]

(10-11-2022, 08:48 PM)rickk Wrote: The real exercise here  is that I need to become more proficient in plotting parallel paths. When you get to a line with a radius, simply moving the previous path don't cut it. Using the "grid" tool has helped me a lot the last couple days. Perhaps with practice!!  

• Create a center path
  
• On a transparent layer, Edit > Stroke Path in Line mode with a thickness equal to the distance between the path, and Butt ends
  
• Alpha-to-selection to get a selection on the outline
  
• Select > To path to get a path on the outline
  
• `Delete the two end segments
  

In the example below I created 4 parallel lines by stroking the center path twice, one with a 30px line and once with a 60px line.

   

   

[rickk]

That's fantastic!!

[rickk]

Is it true that each stroke requires it's own layer, or am I just missing something obvious?

[Ofnuts]

I used one extra layer on which I stroked first the narrow line, got the alpha and path, and then stroked the wide line and got the alpha and path.

[rickk]

Well, it works great, I am thankful for the knowledge. I'm probably going to have to give some consideration to "why" this works, in order to get a handle on it.
But for instance.....having already drawn the black lines on a transparent layer (per your guidance), I found that upon repeating the procedure for the green lines, gimp wanted to draw the green over the top of the black.....unless/until I created an additional transparent layer for the green lines. And same for the red. (red wanted to draw over the green until an additional transparent layer was created just for it) Not a problem, per se, just trying to get a grasp upon what's going on.

Thanks again.

[rickk]

Further experimentation and I see the issue I was having was with the "alpha-to-selection" function on the second (and subsequent) pairs of lines....the "selection" aspect was selecting prior pairs of lines in addition to the ones being drawn.  Not at all any problem so long as all pairs being drawn are the same color. But when trying to change colors between strokes, putting each different color on it's own layer, solved that issue. 

Works great for any needs I'm likely to have, so I'm most beholding to you for the tutelage. 

And, curiosity now piqued, I can see that whole menu area around "alpha-to-selection" is an area where I need to spend some time. 

  

Thanks again!!

[Ofnuts]

OK time for the big tease... with a slight modification to my ofn-gradient-path, making railroad tracks can be a snap.

You define a path which is the center of the tracks

   

You create a sleeper brush and use Edit > Stroke path with an adequate spacing and Track direction dynamics to layout the sleepers.

   

You prepare a half railtrack gradient start starts with transparency and ends with the track.

   

You use ofn-gradient-along-path to draw the track, using the center path (width should be  

   

One could even go as far as scripting the whole thing...

Now, I say it's a tease, because the current published version of ofn-gradient-along-path doesn't support transparency inside the gradient. With the current OGAP, you have to create the tracks using OGAP on a new layer. The center of the gradient will be opaque, so you have to stroke the path again with the Eraser tool to erase the center. So you have one more step but it's still doable.

I'll try to have the new OGAP available soon (but this change opens a big can of worms that I have to check out).