material-maker/addons/material_maker/nodes/runes.mmg

{"name":"runes","node_position":{"x":0,"y":0},"parameters":{"columns":8,"rows":8},"shader_model":{"global":"float ThickLine(vec2 uv, vec2 posA, vec2 posB, float radiusInv)\n{\n\tvec2 dir = posA - posB;\n\tfloat dirLen = length(dir);\n\tvec2 dirN = normalize(dir);\n\tfloat dotTemp = clamp(dot(uv - posB, dirN), 0.0, dirLen);\n\tvec2 proj = dotTemp * dirN + posB;\n\tfloat d1 = length(uv - proj);\n\tfloat finalGray = clamp(1.0 - d1 * radiusInv, 0.0, 1.0);\n\treturn finalGray;\n}\n\n// makes a rune in the 0..1 uv space. Seed is which rune to draw.\n// passes back gray in x and derivates for lighting in yz\nfloat Rune(vec2 uv) {\n\tfloat finalLine = 0.0;\n\tvec2 seed = floor(uv)-0.41;\n\tuv = fract(uv);\n\tfor (int i = 0; i < 4; i++)\t// number of strokes\n\t{\n\t\tvec2 posA = rand2(floor(seed+0.5));\n\t\tvec2 posB = rand2(floor(seed+1.5));\n\t\tseed += 2.0;\n\t\t// expand the range and mod it to get a nicely distributed random number - hopefully. :)\n\t\tposA = fract(posA * 128.0);\n\t\tposB = fract(posB * 128.0);\n\t\t// each rune touches the edge of its box on all 4 sides\n\t\tif (i == 0) posA.y = 0.0;\n\t\tif (i == 1) posA.x = 0.999;\n\t\tif (i == 2) posA.x = 0.0;\n\t\tif (i == 3) posA.y = 0.999;\n\t\t// snap the random line endpoints to a grid 2x3\n\t\tvec2 snaps = vec2(2.0, 3.0);\n\t\tposA = (floor(posA * snaps) + 0.5) / snaps;\t// + 0.5 to center it in a grid cell\n\t\tposB = (floor(posB * snaps) + 0.5) / snaps;\n\t\t//if (distance(posA, posB) < 0.0001) continue;\t// eliminate dots.\n\t\t// Dots (degenerate lines) are not cross-GPU safe without adding 0.001 - divide by 0 error.\n\t\tfinalLine = max(finalLine, ThickLine(uv, posA, posB + 0.001, 20.0));\n\t}\n\treturn finalLine;\n}\n\n\n","inputs":[],"instance":"","name":"Runes","outputs":[{"f":"Rune(vec2($columns, $rows)*$uv)","type":"f"}],"parameters":[{"default":0,"label":"","max":32,"min":2,"name":"columns","step":1,"type":"float","widget":"spinbox"},{"default":0,"label":"","max":32,"min":2,"name":"rows","step":1,"type":"float","widget":"spinbox"}]},"type":"shader"}