I was wondering if anybody may be able to help me. I created a 10x10 matrix out of ws2812B leds and I would like to have the letter E in the middle of it and the surrounding leds go through the rainbow, chaser and all the animations available. I figure there must be a way to tweak the fast led code to allow this I just have no clue. Any help would be greatly appreciated.
Do you want the E to be a solid color? You could just black out those pixels. Following for a higher tech solution though 
At first i thought of doing a solid white but a black out E might be just as good.
It might actually be better considering that in my experience solid white never really looks right on ws2812bs. But I also think you could probably make an XY map and reassign the pixels. I’ve just never done it with pixels that were actually there, only ones that didn’t exist. Are you planning to diffuse it?
yea i have frosted glass about an inch away with a foam board grid separating each led
I would do all the animation for the whole 10x10 matrix and just before FastLED.show give all the pixels belong to E a color of your choice
How do I create an array for the leds I want to turn black? Ive been looking through the library and cant seem to get it.
Trevor Rau
Check this example out
A lot of stuff here to help you with the XY matrix
Im sorry im not really getting it. I just want to say, make LEDS #,#,#,#,#… (0,0,0). I thought i could define and call a array but i dont know how to start it. The example you gave, i can sorta follow but its too complicated for me to manipulate.
Thanks
Define a letter E array like this
const uint8_t LetterE[] = {
0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13,
};
const uint8_t LetterE[] = {24,25,34,44,45,54,64,65};
CRGB.LetterE(0,0,0);
// send the ‘leds’ array out to the actual LED strip
FastLED.show();
// insert a delay to keep the framerate modest
FastLED.delay(1000/FRAMES_PER_SECOND);
This is in the DemoReel100. Does this look ok?