add stripes to a bus image

[dannysprogis]

Greetings,

I am very new to Gimp and really enjoy the functions that I am able to use but i have a small project that I don't even know how to begin and would really appreciate some help with please. 

I have a PNG image of a white bus that I need to paint some graphics on. Basically I need some orange stripes diagonally on the bus. I would like the stripes to be solid and evenly spaced diagonally on the body work and transparent over the windows and of course it must look like a paint job on the bus. 

Can anyone help me get started as I don't even know what functions I need to use and Googling and YouTubing isn't giving me the answers i want because i don't know what to search for. 

 Please see the blank bus attached and a basic idea (painted bus sample)  of what i am aiming to achieve. 

Thank you in advance.

Danny

[denzjos]

1/ make new layer
2/ fill layer with pattern (yellow and black stripes)
3/ gimp menu : Colours / Colour to alpha (choose for color: black)
4/ now you have a layer with yellow stripes
5/ duplicate that layer
6/ make a selection on the bus for the windows 
7/ inverse that selection
8/ select the first layer wit the yellow stripes and press 'delete' on you keyboard
9/ make a selection for the rest of the bus
10/ inverse that selection
11/ select the copied layer with the yellow stripes and press 'delete' on your keyboard
12 on both layers with the yellow stripes, play with the 'Opacity' 

Here a rough selection on the bus :

   

[dannysprogis]

Awesome, sounds like pretty clear instructions, ill see what i can do now!

Thanks !

[tmanni]

(05-04-2020, 07:57 AM)denzjos Wrote: 1/ make new layer
2/ fill layer with pattern (yellow and black stripes)
3/ gimp menu : Colours / Colour to alpha (choose for color: black)
4/ now you have a layer with yellow stripes

For a more control of the stripes, you can use the Filters > Generic > Gegl graph... with this content:

Code:

grid
line-color=yellow
x=120
line-width=60
line-height=0

rotate
degrees=-45

line-color is the stripe color (you can use a rgba notation: line-color="rgba(1.0, 0.0, 0.0, 0.5)" for a semi transparent red)
x is the distance between each stripe.
line-width is the width of each stripe.
degrees controls the rotation of the stipes.

[denzjos]

tmanni, thanks for the code , nice !

[rich2005]

It is all in making a decent mask, then a bit of bump-mapping.

However for the stripes there is symmetry painting, one of the options is tiling. All it takes is one diagonal brush stroke.

   

Going back a bit, another example  https://www.gimp-forum.net/Thread-Image-...21#pid6521

[Ofnuts]

A third way is to:

• set your foreground and backrground colors to yellow and black,
  
• set the gradient to FG to BG (hard edge), 
  
• use the blend tool with Shape: Linear and Repeat: Sawtooth
  
• In Gimp 2.10 you can even adjust the midpoint interactively to set the ratio of the stripes