Currently I just randomly drawing right leaning segments with lighter colour, and sometimes It looks better sometimes it doesn't. But I don't understand what kind of pattern should I follow.
I find using gradients with a bunch of semi-random grey stops can replicate a chrome mirrored effect pretty well. It helps if there’s some lighter points towards the top, but also a nice reflection from the ground.
For a bit of fun, you can also overlay another gradient with some colour in it. I’m using a gradient from solid purple at 0% opacity to 100% opacity for the
Purple Gradient layer below.
The example below was created really quickly, using Dan Fessler’s HD index painting for some automated lo-fi dithering.
And, from there you can hand tweak to get things exactly as you’d like.
The same technique can work for other shapes and gradient types.
I don't do a great deal of pixel art, but I do create a lot of vectors with pseudo-metallic appearances.
In my experience, there is no specific pattern you need to follow to give the impression of metallics. Primarily because in life there's nothing consistent and every pattern is different based upon ambient lighting, surrounding reflective materials, cast highlights and shadows. There's no absolute pattern anywhere in nature, so you don't need one either.
Use whatever you feel works.
There are a few things I do overall for metallics, but these are absolutely not "rules" or restrictions. They are just personal "trends' i seem to follow:
- Remain consistent with whatever pattern in use, based on percieved underlying material. What the pattern is doesn't matter overall. I do tend to stick to 3 values.... dark, medium (base), and light. Every "gold" object should use the same pattern. Every "steel" object should use the same pattern. But gold and steel should have slightly different patterns to help further differentiate them visually.
- Remain consistent with lighting direction. If gold has a 45° pattern, steel should have a 45° pattern, silver should have a 45° pattern, etc.
- If giving depth to a side face or trying to give the impression of edge depth, reverse the angle of the pattern. That is, if the front face has a 45° highlight pattern, for a side face or edge, use a -45° pattern - this helps create a visual edge with color/shading.