How to draw an effect (Gloss with metallic lustre) on concentric circle such as following?

Question

I referred to following article. What I actually need to draw is concentric/ Concrete circles with an effect as shown in image below.

I am finding it difficult to a) Draw the white streaks radially b) Find some key terms to search for related articles to proceed further on this.

Any hint or link to read about this will be of great help.

Manolete

Directly Use high-res image instead of drawing. :) – Infralapsarian

Circular gradient + image with thin, concentric rings? – Semiquaver

Answer 1

I don't have any code for you but the idea is actually quite simple. You're drawing a number of lines radiating from a single, central point (say 50,50) to four different sets of points. First set is for x = 0 to 100, y = 0. Second set is for y = 0 to 100, x = 0. Third set is for x = 0 to 100, y = 100. Fourth set is for y = 0 to 100, x = 100. And for each step you need to either change the colour from white to black or white to grey in increments or use a look up table with your colour values in it.

Mechanotherapy

Answer 2

Try these

Metallic Knob

Metallic Knob 2

Appoint

Both these approaches use images as their base image. – Manolete

Answer 3

http://maniacdev.com/2012/06/ios-source-code-example-making-reflective-metallic-buttons-like-the-music-app

This is a tutorial on making reflective metal buttons. You can apply the techniques from the source code to whatever object you're trying to make. The source code is found here on github. I just googled "ios objective c metal effect" because that's what you're trying to do, right? The metal effect appears in concentric circles and changes as you tilt your phone, just as the iOS6 music slider does.

Herbartian

Most of these examples use a base image which is predefined for Metallic gloss. Is it really not feasible to draw these rings by passing their base color as user input, i.e the code has to be independent of any image. Any clues ? – Manolete

@RahulSharma I have not found anything that does not use a base image, sorry. – Herbartian