diff --git a/2020/sketch_2020_12_17a_3D_revolve/sketch_2020_12_17a_3D_revolve.gif b/2020/sketch_2020_12_17a_3D_revolve/sketch_2020_12_17a_3D_revolve.gif
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Binary files /dev/null and b/2020/sketch_2020_12_17a_3D_revolve/sketch_2020_12_17a_3D_revolve.gif differ
diff --git a/2020/sketch_2020_12_17a_3D_revolve/sketch_2020_12_17a_3D_revolve.pyde b/2020/sketch_2020_12_17a_3D_revolve/sketch_2020_12_17a_3D_revolve.pyde
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--- /dev/null
+++ b/2020/sketch_2020_12_17a_3D_revolve/sketch_2020_12_17a_3D_revolve.pyde
@@ -0,0 +1,97 @@
+from villares import ubuntu_jogl_fix
+
+# 3D studies with Julio Mariutti
+# inspired by: https://seoi.net/peni3d/
+
+points = []
+rot_y = 0
+meridians = 24
+
+def setup():
+    size(500, 500, P3D)
+    strokeWeight(2)
+    noFill()
+    colorMode(HSB)
+
+def draw():
+    global tmouseX, tmouseY
+    translate(width / 2, height / 2)
+    tmouseX, tmouseY = mouseX - width / 2, mouseY - width / 2
+    rotateY(rot_y)
+    background(0)
+    
+    pm = int(len(points) / 2)  # indice do ponto medio
+    # if pm > 0:
+    #     circle(points[pm][0], points[pm][1], 15)
+    # for p in points:
+    #     circle(p[0], p[1], 5)
+    
+    paralelos = []
+    mx, my = 0, 0  # middle
+    for a, b in zip(points[:pm], points[-1:pm - 1:-1]):
+        d = dist(a[0], a[1], b[0], b[1])
+        mx, my = (a[0] + b[0]) / 2.0, (a[1] + b[1]) / 2.0
+        ang = atan2(b[1] - a[1], b[0] - a[0]) + PI
+        circulo = [rotate_p(x, y, ang, mx, my) + (z, )
+                   for x, y, z in z_circle(mx, my,
+                                           d / 2.0,
+                                           num_points=meridians)]
+        paralelos.append((d, circulo))
+
+    for d, circulo in paralelos:
+        stroke(d % 256, 255, 255)
+        beginShape()
+        for x, y, z in circulo:
+            vertex(x, y, z)
+        endShape(CLOSE)
+        
+    stroke(128)
+    for i in range(meridians):
+        beginShape()
+        for d, circulo in paralelos:
+            x, y, z = circulo[i]
+            vertex(x, y, z)
+        vertex(mx, my, 0)
+        endShape()
+
+    stroke(255)    
+    beginShape()
+    for p in points:
+        vertex(p[0], p[1], 0)
+    endShape()
+
+def mousePressed():
+    points[:] = []
+    points.append((tmouseX, tmouseY))
+
+def mouseDragged():
+    if dist(tmouseX, tmouseY,
+            points[-1][0], points[-1][1]) > 15:
+        points.append((tmouseX, tmouseY))
+
+
+def keyPressed():
+    global rot_y
+    if keyCode == LEFT:
+        rot_y -= radians(5)
+    if keyCode == RIGHT:
+        rot_y += radians(5)
+    if key == ' ':
+        rot_y = 0
+
+def z_circle(x, y, radius, num_points=16):
+    passo = TWO_PI / num_points
+    ang = 0
+    pts = []
+    while ang < TWO_PI:  # enquanto o ângulo for menor que 2 * PI:
+        sx = x + cos(ang) * radius
+        sz = 0 + sin(ang) * radius
+        pts.append((sx, y, sz))
+        ang += passo  # aumente o ângulo um passo
+    return pts
+
+def rotate_p(xp, yp, angle, x0=0, y0=0):
+    x, y = xp - x0, yp - y0  # translate to origin
+    xr = x * cos(angle) - y * sin(angle)
+    yr = y * cos(angle) + x * sin(angle)
+    return (xr + x0, yr + y0)
diff --git a/README.md b/README.md
index e84de67a..574ebb77 100644
--- a/README.md
+++ b/README.md
@@ -24,6 +24,15 @@ Here are listed some of the tools I have been using:
 
 ## [2018](2018.md) | [2019](2019.md) | 2020
 
+---
+
+![sketch_2020_12_17a_3D_revolve](2020/sketch_2020_12_17a_3D_revolve/sketch_2020_12_17a_3D_revolve.gif)
+
+[sketch_2020_12_17a_3D_revolve](https://github.com/villares/sketch-a-day/tree/master/2020/sketch_2020_12_17a_3D_revolve) [[Py.Processing](https://villares.github.io/como-instalar-o-processing-modo-python/index-EN)]
+
+3D studies with [Julio Mariutti](), inspired by: https://seoi.net/peni3d/
+
+
 ---
 
 ![sketch_2020_12_16c_recursive_grid](2020/sketch_2020_12_16c_recursive_grid/sketch_2020_12_16c_recursive_grid.gif)