Pantheon Benchmark: Claude Code 2.1 / Sonnet 4.6

// Pantheon - OpenSCAD Model  v4
// Scale: 1 unit ≈ 1m

$fn = 128;

// === Rotunda drum ===
outer_r   = 28;
wall_t    = 6;
inner_r   = outer_r - wall_t;   // 22
drum_h    = 22;

// === Dome (oblate spheroid exterior) ===
dome_a    = outer_r;   // horizontal semi-axis
dome_b    = drum_h;    // vertical   semi-axis  → dome height ≈ drum height
oculus_r  = 4.0;
t_top     = acos(oculus_r / dome_a);   // ≈ 81.8°
n_rings   = 7;
cornice_h = 1.5;       // drum cornice ring height

// === Portico ===
col_r     = 0.75;
col_h     = 13.5;
n_fc      = 8;
col_ws    = 4.25;
col_ds    = 4.5;
ent_h     = 2.8;
ped_h     = 5.0;

// === Connection block ===
conn_w    = 21.0;
conn_d    = 7.5;

// === Steps ===
sn        = 3;
sh        = 0.65;
sr        = 1.4;

// ============================================================
// Derived values
// ============================================================
row3_y    = -(outer_r + conn_d);
row2_y    = row3_y - col_ds;
row1_y    = row2_y - col_ds;

plat_h    = sn * sh;                              // 1.95
col_top_z = plat_h + 0.45 + col_h + 1.6;         // top of column assembly ≈ 17.5
ent_top_z = col_top_z + ent_h;                    // top of entablature ≈ 20.3

portico_w = (n_fc - 1) * col_ws + col_r * 5;
portico_d = abs(row1_y) - outer_r - conn_d + col_r + 0.5;
front_y   = row1_y - col_r - 0.5;

// Entrance door in drum face (where connection block meets rotunda)
door_w    = 8.0;
door_h    = 12.0;

function cx(i) = (i - (n_fc - 1) / 2.0) * col_ws;

// ============================================================
// Modules
// ============================================================

module single_column() {
    // Plinth
    cylinder(h = 0.45, r = col_r + 0.28, $fn = 32);
    // Tapered shaft
    translate([0, 0, 0.45])
        cylinder(h = col_h, r1 = col_r, r2 = col_r * 0.87, $fn = 32);
    // Capital neck
    translate([0, 0, 0.45 + col_h])
        cylinder(h = 0.6, r1 = col_r * 0.87, r2 = col_r * 0.92, $fn = 32);
    // Capital abacus flare
    translate([0, 0, 0.45 + col_h + 0.6])
        cylinder(h = 0.55, r1 = col_r * 0.92, r2 = col_r + 0.52, $fn = 32);
}

module drum() {
    difference() {
        union() {
            // Main cylindrical wall
            cylinder(h = drum_h, r = outer_r);

            // 5 structural buttresses: sides + back (skip front ±45° sector)
            butt_w = 7.5;
            butt_d = 2.0;
            for (ang = [90, 135, 180, 225, 270]) {
                rotate([0, 0, ang])
                translate([outer_r, -butt_w / 2, 0])
                    cube([butt_d, butt_w, drum_h]);
            }
        }

        // Hollow interior
        translate([0, 0, -0.5])
            cylinder(h = drum_h + 1, r = inner_r);

        // Entrance doorway cut (front face)
        translate([-door_w / 2, -(outer_r + 0.1), 0])
            cube([door_w, wall_t + 0.2, door_h]);
    }

    // Upper cornice ring at top of drum
    translate([0, 0, drum_h])
        difference() {
            cylinder(h = cornice_h, r = outer_r + 1.5);
            translate([0, 0, -0.5])
                cylinder(h = cornice_h + 1, r = outer_r - 0.5);
        }

    // Mid-drum cornice band (divides lower and upper drum zones)
    mid_z = drum_h * 0.47;
    translate([0, 0, mid_z])
        difference() {
            cylinder(h = 1.0, r = outer_r + 0.9);
            translate([0, 0, -0.5])
                cylinder(h = 2.1, r = outer_r - 0.4);
        }

    // Low base podium ring
    translate([0, 0, -1.5])
        difference() {
            cylinder(h = 1.5, r = outer_r + 2.5);
            translate([0, 0, -0.5])
                cylinder(h = 2.6, r = outer_r - 1.0);
        }
}

module dome() {
    translate([0, 0, drum_h + cornice_h]) {
        difference() {
            union() {
                // Oblate-spheroid stepped exterior
                for (i = [0 : n_rings - 1]) {
                    t1 = i       * t_top / n_rings;
                    t2 = (i + 1) * t_top / n_rings;
                    r  = dome_a * cos(t1);
                    h1 = dome_b * sin(t1);
                    h2 = dome_b * sin(t2);
                    translate([0, 0, h1])
                        cylinder(h = h2 - h1, r = r);
                }
            }

            // Hollow interior — hemisphere
            translate([0, 0, -1.0])
                sphere(r = inner_r + 0.6);

            // Oculus opening
            h_oc = dome_b * sin(t_top) - 0.6;
            translate([0, 0, h_oc])
                cylinder(h = dome_b + 2, r = oculus_r);

            // Clean below base
            translate([0, 0, -(dome_b * 3)])
                cylinder(h = dome_b * 3, r = dome_a * 3);
        }

        // Oculus collar ring
        h_oc = dome_b * sin(t_top) - 0.4;
        translate([0, 0, h_oc])
            difference() {
                cylinder(h = 1.5, r = oculus_r + 1.8);
                translate([0, 0, -0.5])
                    cylinder(h = 3.0, r = oculus_r);
            }
    }
}

module connection_block() {
    // Solid rectangular body connecting portico to rotunda.
    conn_h = ent_top_z;
    difference() {
        union() {
            translate([-conn_w / 2, -(outer_r + conn_d), 0])
                cube([conn_w, conn_d, conn_h]);
            // Matching cornice on top
            translate([-conn_w / 2 - 1.0, -(outer_r + conn_d), conn_h])
                cube([conn_w + 2.0, conn_d, 0.8]);
        }
        // Entrance doorway cut through connection block front face
        translate([-door_w / 2, -(outer_r + conn_d) - 0.1, 0])
            cube([door_w, conn_d + 0.2, door_h]);
    }
}

module portico_platform() {
    translate([-portico_w / 2, front_y, 0])
        cube([portico_w, portico_d, plat_h]);
}

module steps() {
    for (s = [0 : sn - 1]) {
        depth = (sn - s) * sr;
        w     = portico_w + (sn - s) * sr * 2.6;
        h     = (sn - s) * sh;
        translate([-w / 2, front_y - depth, 0])
            cube([w, depth + 0.01, h]);
    }
}

module entablature() {
    // Beam spanning full portico width and depth
    translate([-portico_w / 2, front_y, col_top_z])
        cube([portico_w, portico_d, ent_h]);
    // Wrap over connection block front face (thin fascia)
    translate([-conn_w / 2, row3_y, col_top_z])
        cube([conn_w, conn_d, ent_h]);
}

module pediment() {
    // rotate([90,0,0]) makes polygon-Y → world+Z, extrusion-Z → world-Y
    translate([0, front_y + portico_d, ent_top_z])
        rotate([90, 0, 0])
        linear_extrude(height = portico_d)
        polygon([
            [-portico_w / 2, 0],
            [ portico_w / 2, 0],
            [0, ped_h]
        ]);
}

module portico_columns() {
    translate([0, 0, plat_h]) {
        // Row 1 — front: all 8 columns
        for (i = [0 : n_fc - 1])
            translate([cx(i), row1_y, 0]) single_column();

        // Row 2 — outer 4 + two framing central doorway
        for (i = [0, 1, n_fc - 2, n_fc - 1])
            translate([cx(i), row2_y, 0]) single_column();
        translate([cx(2),      row2_y, 0]) single_column();
        translate([cx(n_fc-3), row2_y, 0]) single_column();

        // Row 3 — outer 2 + inner pair at doorway
        translate([cx(0),      row3_y, 0]) single_column();
        translate([cx(n_fc-1), row3_y, 0]) single_column();
        translate([cx(2),      row3_y, 0]) single_column();
        translate([cx(n_fc-3), row3_y, 0]) single_column();
    }
}

// ============================================================
// Assembly
// ============================================================
color([0.82, 0.79, 0.72]) {
    drum();
    dome();
    connection_block();
    portico_platform();
    steps();
    entablature();
    pediment();
    portico_columns();
}