Apply a conic gradient on a specific angle - how to ? ( radar screen scanning )

[semar]

Hi all, I'm new to Paint.Net, and I would like to paint the beam of a radar with a circular gradient.

To better understand what I mean, here is what I would like to achieve:

radar

I would like to build two images. The first ist the grid (I didn't try yet but I think it is not soooo complicated). The second image is the beam, which seems a conic gradient (from green to black) which spreads on an angle, say, of 30 degrees. In my application, the beam image should rotate above the grid image, in order to achieve the radar-beam effect (both images will be "blended" togheter, so that the beam image does not mask the grid image below).

 

I can indeed obtain a similar beam, but the conic gradient makes the gradient from, say, green to black from 0 to 180 degrees. What I need, however, is to limit the gradient only to, say, 0 to 30 degrees.

 

I've tried also the circular gradient, and also played with the filling-type, but I can't achieve what I want.

 

So the question, is there any setting in order to apply a conic gradient only to a certain degrees range ?

 

Thanks in advance and have a nice day,

Sergio

Edited March 8, 2023 by semar

[frio]

You could try making a conic gradient with black and white, then using the Levels adjustment (control-L) to compress the range.

 

If you wanted a slice that's compressed to about 30 degrees, using input levels low: 234 (about 330/360*255), high: 255 gets you that.

 

You can also adjust the high end of the input levels to compress it towards white instead of black.

[Pixey]

Hello @semar and welcome to the forum  

 

Here are a few 'idea' steps.  I used @BoltBait's Grid maker, which is found in his pack.

 

Once you make the gradient, as per the template, you can then go back and select

a bigger circle and add some more gradient.

[semar]

First of all, many thanks for your kind and prompt answers @frio and @Pixey !

Dear Pixey, I've followed your - very helpful - step by step guide, and indeed I've succeeded quite everything ! By the way, I've done the simmetric circles using the "target" shape, it makes "regular" circles if you didn't know 🙂

 

What I still did not achieved are two things:

 

1. The cone template. I do can make it using the cone shape and rotate it using the ctrl+shift+z = zoom tool, but the "round" part (which is the shorter side of the cone )  is not so precise like your one, that follow the big circle path. My cone has "rounded" vertices, and the curve at the round side - if you get what I mean - does not follow the circular path of the big external circle (the target).

I guess it's a matter of drag some point here and there, but the two vertices at the bottom still remain "round". I hope you can understand my "english" - sorry !

 

2. the gradient part. I still have to understand what does frio mean - thank you again frio by the way ! - with the "Levels adjustment (control-L) to compress the range". You see, I'm a beginner with Paint.net.😉

And also I have to get your last step, "primary color at 255 & secundary transparent". I understand this sentence (horray ! 😉 ) but I don't know how do you use the gradient tool here.

Same for "Once you make the gradient, as per the template, you can then go back and select a bigger circle and add some more gradient."

Which makes sense for all of you, but me 😉 - I have to work on it !

 

Anyway your hints have helped me a lot ! Now with a fresh mind I'll try again to get that "Gradient with compressed range". I'll keep you informed 😉

 

By the way, who makes all these cool plugins ? And which are the steps and the programming-language to use in order to program such a plugin ? I'm just curious 🙂

 

Have a nice day and thanks again for your help,

Sergio

 

P.S.: My achievement so far:

 

Edited March 9, 2023 by semar

[semar]

Getting there.. but I don't really know how I did that ! 😉

Still have to work on the curved vertices, and the base of the cone, which does not follow the curve of the target..

[Lemonade]

Hey @semar,
I would go with circle and triangle to create a cone, where circle is the same size as your outer (biggest) green circle. Then add a triangle and where both shapes intersect, use lasso tool to delete that area. Attached an example.
 

Edited June 28, 2023 by Lemonade

[semar]

Cheers Lemonade,

that is indeed a good idea !

Now I'll investigate on how to draw a circle around another one, and how to use effectively the lasso..

 

Thanks a lot !

Have a nice day,

Sergio

[semar]

While trying, I've discovered that instead of backcolor transparent, I can get better results with backcolor black.

And Level adjustments makes wonder 🙂

Perhaps there's a better way as Pixey suggested, but right now I don't know which mouse-moves have to be done while using the conic gradient..

I had to change the layer orders though.. now the "gradient" layer is the second one from below.

Perhaps using transparent instead of black would be far more better, however I don't get the same behaviour using the Level adjustment tool.

Oh my. This is the result so far, which is not bad for a newby 😉

 

 

Edited March 9, 2023 by semar

[Pixey]

I hope this video will help you @semar in how to use the Gradient Tool  

 

 

 

[semar]

Dear Pixey,

you've made my day !

 

Thousend thanks ( mille grazie ) for your kind tutorial ! I've learned more from it than from other hundreds videos ! - Really !

 

Please leave it online, I'll watch it again (and again..)  later and will follow your instruction !

 

You use a linear gradient - that makes the trick.. I thought, I need a conic gradient..

 

Many many thanks dear Pixey ! Really very kind of you ! I *do* appreciate your time and effort  🙂  🙂 

 

Best regards and have a nice day,

Sergio

 

Edited March 9, 2023 by semar

[Pixey]

I'm so happy you found it useful @semar  Yes, the video will remain on YouTube now forever  

 

Happy PDNing 🎨