Dots.osl

// Random circles (or spheres, really) with outputs
// for bump, random factor, etc. Can be made to make
// very cool random candy cover, paint flakes...
//
// Dots.osl, by Zap Andersson
// Modified: 2019-11-10
// Copyright 2019 Autodesk Inc, All rights reserved. This file is licensed under Apache 2.0 license
//    https://github.com/ADN-DevTech/3dsMax-OSL-Shaders/blob/master/LICENSE.txt
// Modified: 2020-1-15 by Saul Espinosa for Redshift 3D

shader Candy
[[ string help="Random circles with random colors and a tunable bump output. For random dots or candy sprinkles.",
   string category = "Textures",
   string label = "Random Dots"
]]
(
	// For convenience, default to object space
	// You can connect any other coordinate space
	// as input anyway...
	point UVW    = transform("object", P) [[ string help = "The position input, defaulting to object space. Connect an UVW shader for other alternatives." ]],
	float Scale  = 0.01 [[float min = 0, float max = 25]],
	float Radius = 0.5      [[ float min=0.0, float max=2.0 ]],
	int   RandomOverlap = 0 [[ string widget = "checkBox" ]],
	float BumpAmount = 1.0 [[float min = 0, float max = 5]],
	float BumpShape  = 1.0 [[float min = 0, float max = 25]],

	output color Col    = 0,
	output float Fac    = 0,
	output float Bump   = 0,
	output float Dist   = 0,
	output float Rnd    = 0
)
{
	point pnt = UVW / Scale;	
	float pri = -1;
  
	// Standard method for randomization:
  	// Go through a 3x3x3 grid that we offset
  	for (float x = -1; x <= 1; x++)
	{
    	for (float y = -1; y <= 1; y++)
		{
			for(float z = -1; z <= 1; z++)
			{
				// Point that sources all our randomization
				// We run these through cell noises to get
				// random values
				// MAXX-44914 fix: Adds the 0.001 offset and floor()
				point rndpoint = floor(pnt) + point(x, y, z) + 0.001;				
				// Compute a center 
				point dotcenter = rndpoint + noise("cell", rndpoint, 1);				      
				float dist      = distance(dotcenter, pnt);
				// Randomize the priority, all they all look "stacked" in 
				// the same direction if they overlap
				float priority = noise("cell", rndpoint, 2);

				// If within the radius, and priority is higher
				if (dist < Radius && priority > pri)
				{
					pri = priority;
					
					Col    = noise("cell", rndpoint, 3);
					Dist   = dist / Radius;
					Bump   = pow(sin((1.0 - Dist) * 1.58), BumpShape) * BumpAmount;
					Fac    = 1.0;
					Rnd    = priority;
					
					// If we exit early, shader is more efficient,
					// but any "overlap" becomes completely sorted 
					// in an X/Y/Z order and looks fake.
					if (!RandomOverlap)
						return;
				}
			}
		}
	}
}