size: 7  17.3mm  (ETBuilder size 7.25 which makes 7)


       MEASUREMENTS FROM WEB

SIZE --------- BASE ------------     ----- CLAWS ----    ----- STONE -----    GIRDL  TO   CIRCUM STN    GAP
                                                                                    CULET FRENCE  
.10  3.06  4.10  1.68  1.60  .07  |  0.91  3.16  2.75  |  2.65  3.69  1.64  |  1.24  0.81  67.25  23   0.27
.20  3.85  5.16  1.94  1.85  .08  |  1.15  3.97  3.46  |  3.33  4.64  2.07  |  1.56  0.74  68.84  20   0.10
.25  4.13  5.54  2.08  1.99  .09  |  1.21  4.26  3.72  |  3.57  4.98  2.22  |  1.67  0.76  69.70  19   0.09
.30  4.39  5.89  2.21  2.11  .10  |  1.31  4.53  3.95  |  3.79  5.29  2.35  |  1.77  0.78  70.48  18   0.11  SO S/B 17 STONES
.50  5.22  7.00  2.26  2.15  .10  |  1.40  5.05  4.70  |  4.51  6.30  2.80  |  2.11  0.49  70.74  15   0.19
.70  5.80  7.78  2.30  2.20  .10  |  1.40  5.31  5.22  |  5.02  7.00  3.11  |  2.35  0.30  71.01  14   0.05

      FROM JVJ
                METAL HEIGHT IS 
                A GIVEN INPUT          ADJ
.10                 1.60                                                             0.76  66.53  23   0.24
.20                 1.85                                                             0.74  68.29  19   0.26                 
.25                 1.99                                                             0.79  69.36  18   0.28
.30                 2.11  = 2.32       .21                                           1.06  71.69  18   0.18
.50                 2.15                                                             0.62  70.87  15   0.21
.70                 2.20  = 2.42       .21   +HIGHER METAL .10                       0.70  72.82  14   0.18


uncomment zoom limits


If the object appears dull or overly matte, consider:

roughness: 0.2,       // Less diffuse, more shine
clearcoatRoughness: 0.1,  // Slight blur to coat
envMapIntensity: 1.0, // Brighter reflections

changed yellow gold



To transform a tube segment along an arc of radius 7 to one along radius 6, while keeping the same wall thickness, you're essentially "shrinking" the center path of the tube inward, but adjusting the geometry so that the inner/outer surfaces maintain the same distance apart.

This is a classic radial deformation, often used for resizing ring shanks or resizing curved bands.

🧠 Key Concept
You want to map every point (x, y, z) in the original geometry to a new position closer to the origin radially, but you must ensure that the radial thickness is preserved.

🔍 Assumptions
The original arc lies in the XY plane (Z is up).

The centerline of the arc is a portion of a circle with radius 7 centered at (0, 0).

The tube has a circular or elliptical cross-section that sits on this centerline.

✅ Step-by-Step Transformation
For every vertex in the geometry:

Get the 2D radius of the point in the XY plane:

basic
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R0 = SQR(x*x + y*y)
Find the radial offset from the arc centerline (radius 7):

basic
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offset = R0 - 7
New radius after shrinking arc to radius 6:

basic
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R1 = 6 + offset
Scale x and y to lie on new radius:

basic
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scale = R1 / R0
newX = x * scale
newY = y * scale
newZ = z   ' Z remains unchanged
This moves the point toward (or away from) the origin, so it follows the arc of the new radius 6, but keeps the same radial thickness from the centerline.

💡 Why This Works
You’re converting each vertex’s distance from the original arc into a distance from the new arc, preserving the relative offset from the curve centerline. This keeps the geometry's wall thickness intact.

📌 PBCC6 Pseudocode Example
basic
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FOR i = 0 TO numVertices - 1
    x = vertex(i).x
    y = vertex(i).y
    z = vertex(i).z

    r0 = SQR(x * x + y * y)
    offset = r0 - 7
    r1 = 6 + offset
    IF r0 <> 0 THEN
        scale = r1 / r0
    ELSE
        scale = 1
    END IF

    vertex(i).x = x * scale
    vertex(i).y = y * scale
    vertex(i).z = z
NEXT









✅ Option 3: Subdivide Large Triangles
To actually add more triangles (and smooth geometry), use:

🔧 THREE.SubdivisionModifier (from examples/jsm/modifiers)
js
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import { SubdivisionModifier } from 'three/examples/jsm/modifiers/SubdivisionModifier.js';

const modifier = new SubdivisionModifier(1); // 1 = one level of subdivision
ETSpinGroup2.traverse(child => {
  if (child.isMesh && child.geometry && child.geometry.isBufferGeometry) {
    const geom = new THREE.Geometry().fromBufferGeometry(child.geometry);
    const subdivided = modifier.modify(geom);
    child.geometry = new THREE.BufferGeometry().fromGeometry(subdivided);
    child.geometry.computeVertexNormals();
  }
});
This adds vertices and makes surfaces smoother, especially curved areas.

⚠️ SubdivisionModifier is CPU intensive. Only apply it once on startup or loading.



to work on:
-----------

build1(val, clicked)
  - iframe.onload never fires

now calculating stones in 9.html and also in contact.exe