How do I display a sector of a circle in decal?

[anonymous_user_43c3993a]

Hi, I’m looking for a way to show an area of effect indicator for skills. The three values I have to display the sector are location (origin of the circle), rotation (facing of indicator), and arc (angle of indicator).

I am using Blueprints.

For context, a sector is like a cone but the outer boundary is circular in nature, as opposed to being a straight line.

Reference:

I don’t need to detect enemies in the sector because I will probably end up using circle detection and then checking the angle between cast origin and target.

I have considered using a sector material, but I’m not sure how I would change the arc.

I have successfully implemented skill range indicators and full circle area of effect indicators, just having trouble with sectors.

Any suggestions or advice would be appreciated. If this is already a function of Unreal Engine, I apologize, as I’m new and can’t find any information about it anywhere. I thought it would be a common topic.

Thanks in advance.

Edit: I technically do not need to use a decal, as long as the desired outcome is achieved.

[Goanna7007]

Use an image like this one, then in the material use an if statement with the white values.

You could use another texture for the circle.

I need to go now but If you need more help comment and I’ll help you in a while.

[anonymous_user_43c3993a]

Wow, nice creative solution! Conceptually I understand what you mean but I don’t know how to implement it. I’ll give it a shot and let you know how it goes. If I haven’t followed up when you return please assume that I haven’t figured it out.

Edit: Got it working! All I need to do now is somehow pass in the threshold.

Edit 2: Got the threshold passed in. Working on angle calculations. Seems like the image you provided isn’t linear. Any idea how I could generate a linear version of what you posted?

[Goanna7007]

This works, however there are some rough edges, this could be fixed with blur or something else.

[anonymous_user_43c3993a]

Thanks, yeah that’s how I ended up implementing it. Again though, the gradient isn’t linear 0-255. The angle and 0-1 inputs can’t be linearly mapped. Look at the resulting angle difference between param = 0.1 and param = 0. Am I doing something wrong?

[Goanna7007]

oh, ok.
I just did the same thing mathematically and works well.

[anonymous_user_43c3993a]

Quick question, what’s TexCood?

[Goanna7007]

That is the uv coordinate, so the center of the UV has a TexCord of (0.5,0.5)

[Goanna7007]

[Goanna7007]

Made the input param linear and degrees

[anonymous_user_43c3993a]

Edit: Sorry didn’t see your linear + degrees stuff above. You are doing God’s work, the hero that we have, not the hero that we deserve!

All fixed man, you’re the best!

[anonymous_user_3ad9ae12]

Thanks to everyone on this thread! It really helped me! Just one question: which scalar-or-whatever controls the radius of the circle?

[ismilawd]

Add center offset, incase of using for annual sector shape.