Bevel a Procedural Texture?

Question

Is it possible to bevel the outline of a procedural texture?

This would be the desired effect (result prepared with an image editor):

For example, we have the default Brick Texture, and its Mortar Size can be thickened, but there is no built-in parameter to taper off the edge with a bevel to give it a more rounded look.

Bricks with the default settings (left) and thickened mortar (right)

The best idea I can think of is to stack Brick Texture nodes of different Mortar Sizes to create a stepped gradient. That however has resolution limitations, plus using that many nodes may negatively impact render time.

So I am wondering if anyone with a bit more vector know-how than myself knows of a way to generate a vector curve that transitions between two mortar sizes to achieve the result more elegantly. Any ideas?

Here is a concept image - the blue curves representing the vector transition:

Answer 1

Based on a modified version of this OSL bricks shader, I added a smoothness parameter that generates a smoother transition from the mortar color to the brick color (Currently will work in the desired manner only with values ranging from 1-10. Will probably improve algorithm tomorrow).

# include "stdosl.h"

shader brick(
    float BMWIDTH = 5,
    float BMHEIGHT = 5,
    float MORTARTHICKNESS = 0.1,
    point Vector = P,
    int   smoothness = 1,
    color Cbrick = color (0.5,0.15,0.14),
    color Cmortar = color(0.5, 0.5, 0.5),
    output color Col_Out = color(0.7)
)

{
    color Ct;
    point Nf;
    float ss;
    float tt;
    float th;
    float sbrick;
    float tbrick;
    float w;
    float h;

    float x = Vector[0];
    float y = Vector[1];

    float smoothnessFac = 0.1;
    for ( int i = 0; i < smoothness; i++ ) {
        float MWF = MORTARTHICKNESS * ( 1 + i * smoothnessFac ) * 0.5 / BMWIDTH;
        float MHF = MORTARTHICKNESS * ( 1 + i * smoothnessFac ) * 0.5 / BMHEIGHT;

        ss = x / BMWIDTH;
        tt = y / BMHEIGHT;

        if (mod(tt * 0.5, 1) > 0.5)
        {
            ss += 0.5;
        }

        sbrick = floor(ss);
        tbrick = floor(tt);

        ss -= sbrick;
        tt -= tbrick;

        w = step(MWF,ss)  - step(1-MWF,ss);
        h = step(MHF, tt) - step(1-MHF, tt);

        if ( i == 0 ) {
            Ct = mix(Cmortar, Cbrick, w*h);
        } else {
            color current = mix(Cmortar, Cbrick, w*h);
            Ct = mix( Ct, current, 1 - i * smoothnessFac );
        }
    }

    Col_Out = Ct;
}

Answer 2

There's something of a workaround, but it stops you from being able to tweak it. Turn all the settings black and white and render it with a shadeless node (hook it up to the emission color) on a plan large enough for your texturing needs. Render and save the image. Blur the edges in an outside image editor, making sure you keep the blurring within the boundaries of the white bricks. Alternately, for a sharper bevel, apply 50% gray to the inner edges of the bricks. Even a gradient out to the black. Then reapply the texture as an image texture displacement.

The gray is what gives it that level difference.

I hope that helps.