Dev news : added gold ore + improved iron ore POM/normals a bit (Patreon)

Trying to keep a good balance between vanilla and realism, I added gold ore that features a pattern similar to iron. I changed some of the fuzz and warping on the gold so it's unique in its own right but still looks close to the intended pattern.

I also tried keeping the original color palette. That being said it's highly dependent on how the shaders will interpret the metal's albedo when using PBR hardcoded f0.

Metals are not supposed to exhibit diffuse lighting (or very little of it) and mostly consist of specular reflections. In Minecraft specular reflections mostly occur thanks to the sun/moon light (because those are directional lights) whereas block lights don't really "emit"  light but instead use a pre-baked lightmap/shadowmap. It's possible to extrapolate the origin of the light from the shadowmap (much like what's done to bring the so-called "directional lightmaps", i.e. per-pixel normal-aware emissive block light) but that is much too inaccurate to be used for speculars.

The only way to have speculars on such light sources is path tracing light from those emissive blocks. With SSPT this can only be done with light sources that are currently displayed on screen, with world-space PT (against a voxelized structure) all light sources can be considered.

The issue being, as metals are only supposed to exhibit specular reflections, most of the time when underground it's impossible to have such reflections for the reasons stated above. For these cases, some shaders use a "fallback" case where if no reflections are present the fallback color will use the albedo/colormap as diffuse (and at the same time the material will not behave as a metal anymore). Shaders using that fallback include Kappa and BSL, AFAIK.

Some shaders such as Continuum 2.1 (as of alpha build 10) also mix some albedo color on the specular reflections. That enabled cases like the Stratum redstone that has a different diffuse color than it's specular reflection, and it looks pretty dope.

Some other shaders might even completely disregard the hardcoded metal value entirely and have yet another results.

With metals, it's hard to predict how they'll look with shaders.

Anyway, here are the shaders I used here:

1-3 : Stratum
4-5 : Kappa v2.2
6     : BSL
7-8 : Continuum 2.1