WLED - nolanhergert/EasyLED GitHub Wiki

Understanding noise1

Original (from FastLED):

Discourse discussion to update: https://wled.discourse.group/t/improving-noise-effects-at-slow-speeds/3180

  • Would like to create a unit test.
  • Need to mock the library calls, or just include them directly! Make a WLED fork with unit test runner. Maybe there's a way to simplify the colormap and inoise16 so you can test and debug with easy graphs visually. Mock inoise16 and sin8 as simple passthroughs of f(x) = x?
    • Where is existing changes? I think on your fork of WLED...
  • Even with the simplest change, I couldn't figure out why it was turning black. At this point, I don't care, as Noise 3 / Noise Pal fit the bill. It's weird. Maybe post to WLED forum?

Chunky shifting at slow speeds

  • Truncation
    • -O2 optimization doesn't change the chunkiness! Even for code right next to each other!
uint8_t noise = inoise16(real_x, real_y, real_z) >> 8;   // get the noise data and scale it down
uint8_t index = sin8(noise * 3);                         // map LED color based on noise data

uint8_t index = sin8(noise * 3);

Other stuff

  • Don't understand why inoise16 is used if it's just going to be right shifted 8 at the end (the precision going in isn't needed!).
  • Doesn't cause chunkiness, but the 2nd i+SEGLEN (should be j+SEGLEN for 2D arrays) is useless and confusing for 1D strips! Instead of a flat line (slope = 0) advancing by step each time, it's now a diagonal (slope = 1) that also advances only by step each time. It happens in other ways inoise(const, const, i*scale + step) ?!?!
uint8_t index = inoise8(i * SEGLEN, SEGENV.step + i * SEGLEN);

Want the shift for noise 2 and 3 to match what is done for Pride 2015. Super slick slow mo instead of just chunky.

mode_noise16_2, mode_noise16_3, https://github.com/Aircoookie/WLED/blob/e04b9656593818694ec498e710d07660656bcc32/wled00/FX.cpp#L1915

Pride 2015: https://github.com/Aircoookie/WLED/blob/e04b9656593818694ec498e710d07660656bcc32/wled00/FX.cpp#L1658

  • SEGMENT.speed: Animation speed
  • SEGENV.step: ?? Environment step (ticks since start) (why does it increment it inside the effect?)
  • Where does fire/intensity go?

Quirks

  • TXD0 is pin 1, and RXD0 is pin 3. Awesome!
  • Need to select checkboxes for all segments you want to "copy exact" and then click the settings you want for both segments. (reapplying them if you already did so)