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Diffstat (limited to 'graphics/sketch/Doc/hand.sk')
-rw-r--r-- | graphics/sketch/Doc/hand.sk | 382 |
1 files changed, 382 insertions, 0 deletions
diff --git a/graphics/sketch/Doc/hand.sk b/graphics/sketch/Doc/hand.sk new file mode 100644 index 0000000000..71cf6c0b57 --- /dev/null +++ b/graphics/sketch/Doc/hand.sk @@ -0,0 +1,382 @@ +% +% Very simple model of my hand +% +% Gene Ressler +% +% In particular, this completely ignores the carpal joints. +% +% Try this with various options to sketch. +% +% -D fist \ +% -D ok > none or one of these +% -D spread / +% +% -D topview \ +% -D frontview > none or one of these +% -D sideview / +% +% -D repeated +% +% I am not responsible for modifications to draw +% obscene gestures. + +% parameterization of model + +% for fingers, 0 is thumb, 1 is index, +% 2 is middle, 3 is ring, 4 is little + +% lateral angle between fingers +def spread_rot + <fist> 0 + <ok> 5 + <spread>10 + <> 0 +% and between thumb and index finger +def spread_rot_0 + <fist> 40 + <ok> 55 + <spread> 55 + <> 25 + +% rotations of finger parts +% distal is the finger tip +% middle is below that +% meta is the knuckle +def distal_0_rot + <fist> 60 + <ok> 45 + <> -10 +def middle_0_rot + <fist> 50 + <ok> 40 + <spread> 0 + <> 10 +def meta_0_rot + <fist> 40 + <ok> 33 + <> 0 + +def distal_1_rot + <fist> 90 + <ok> 60 + <> 0 +def meta_1_rot + <fist> 90 + <ok> 55 + <> 0 + +def distal_2_rot + <fist> 90 + <ok> 30 + <> 0 +def meta_2_rot + <fist> 90 + <ok> 35 + <> 0 + +def distal_3_rot + <fist> 90 + <ok> 30 + <> 0 +def meta_3_rot + <fist> 90 + <ok> 30 + <> 0 + +def distal_4_rot + <fist> 90 + <ok> 30 + <> 0 +def meta_4_rot + <fist> 90 + <ok> 25 + <> 0 + +% end parameters + +% useful stuff +def O (0,0,0) +def I [1,0,0] +def J [0,1,0] +def K [0,0,1] + +% dependent rotations +% fingers have the last two joints wired together +def middle_1_rot distal_1_rot +def middle_2_rot distal_2_rot +def middle_3_rot distal_3_rot +def middle_4_rot distal_4_rot + +% proportions +def proximal_rad .6 +def distal_rad .5 +def distal_len 1.8 +def joint_rad .6 +def joint_gap .7 +def middle_ratio 1.8 +def proximal_distal_ratio proximal_rad / distal_rad + +% primitive segment of a finger is a truncated cone +def segment { + def n_faces 8 + sweep { n_faces<>, rotate(360 / n_faces, [J]) } + line(proximal_rad, 0)(distal_rad, distal_len) +} + +% spheres to connect segments at joints +def joint_sphere { + def n_joint_faces 8 + sweep [fillcolor=red] { n_joint_faces, rotate(360 / n_joint_faces, [J]) } + sweep { n_joint_faces, rotate(180 / n_joint_faces) } + (0, -joint_rad) +} + +% following is five separate definitions for five fingers +% with parameters, this would be much shorter! + +def distal_0 { + put { translate(joint_gap * joint_rad * [J]) + then rotate(distal_0_rot, [I]) + then translate((distal_len + joint_gap * joint_rad) * [J]) } + {segment} + put { rotate(distal_0_rot / 2, [I]) + then translate((distal_len + joint_gap * joint_rad) * [J]) } + {joint_sphere} + put { scale( [J] + proximal_distal_ratio * ([I]+[K]) ) } + {segment} +} + +def finger_0 { + put { translate(joint_gap * joint_rad * [J]) + then rotate(middle_0_rot, [I]) + then translate((middle_ratio * distal_len + joint_gap * joint_rad) * [J]) } + {distal_0} + put { scale(proximal_distal_ratio) + then rotate(middle_0_rot / 2, [I]) + then translate((middle_ratio * distal_len + joint_gap * joint_rad) * [J]) } + {joint_sphere} + put { scale( middle_ratio * [J] + proximal_distal_ratio^2 * ([I]+[K]) ) } + {segment} +} + +def distal_1 { + put { translate(joint_gap * joint_rad * [J]) + then rotate(distal_1_rot, [I]) + then translate((distal_len + joint_gap * joint_rad) * [J]) } + {segment} + put { rotate(distal_1_rot / 2, [I]) + then translate((distal_len + joint_gap * joint_rad) * [J]) } + {joint_sphere} + put { scale( [J] + proximal_distal_ratio * ([I]+[K]) ) } + {segment} +} + +def finger_1 { + put { translate(joint_gap * joint_rad * [J]) + then rotate(middle_1_rot, [I]) + then translate((middle_ratio * distal_len + joint_gap * joint_rad) * [J]) } + {distal_1} + put { scale(proximal_distal_ratio) + then rotate(middle_1_rot / 2, [I]) + then translate((middle_ratio * distal_len + joint_gap * joint_rad) * [J]) } + {joint_sphere} + put { scale( middle_ratio * [J] + proximal_distal_ratio^2 * ([I]+[K]) ) } + {segment} +} + +def distal_2 { + put { translate(joint_gap * joint_rad * [J]) + then rotate(distal_2_rot, [I]) + then translate((distal_len + joint_gap * joint_rad) * [J]) } + {segment} + put { rotate(distal_2_rot / 2, [I]) + then translate((distal_len + joint_gap * joint_rad) * [J]) } + {joint_sphere} + put { scale( [J] + proximal_distal_ratio * ([I]+[K]) ) } + {segment} +} + +def finger_2 { + put { translate(joint_gap * joint_rad * [J]) + then rotate(middle_2_rot, [I]) + then translate((middle_ratio * distal_len + joint_gap * joint_rad) * [J]) } + {distal_2} + put { scale(proximal_distal_ratio) + then rotate(middle_2_rot / 2, [I]) + then translate((middle_ratio * distal_len + joint_gap * joint_rad) * [J]) } + {joint_sphere} + put { scale( middle_ratio * [J] + proximal_distal_ratio^2 * ([I]+[K]) ) } + {segment} +} + +def distal_3 { + put { translate(joint_gap * joint_rad * [J]) + then rotate(distal_3_rot, [I]) + then translate((distal_len + joint_gap * joint_rad) * [J]) } + {segment} + put { rotate(distal_3_rot / 2, [I]) + then translate((distal_len + joint_gap * joint_rad) * [J]) } + {joint_sphere} + put { scale( [J] + proximal_distal_ratio * ([I]+[K]) ) } + {segment} +} + +def finger_3 { + put { translate(joint_gap * joint_rad * [J]) + then rotate(middle_3_rot, [I]) + then translate((middle_ratio * distal_len + joint_gap * joint_rad) * [J]) } + {distal_3} + put { scale(proximal_distal_ratio) + then rotate(middle_3_rot / 2, [I]) + then translate((middle_ratio * distal_len + joint_gap * joint_rad) * [J]) } + {joint_sphere} + put { scale( middle_ratio * [J] + proximal_distal_ratio^2 * ([I]+[K]) ) } + {segment} +} + +def distal_4 { + put { translate(joint_gap * joint_rad * [J]) + then rotate(distal_4_rot, [I]) + then translate((distal_len + joint_gap * joint_rad) * [J]) } + {segment} + put { rotate(distal_4_rot / 2, [I]) + then translate((distal_len + joint_gap * joint_rad) * [J]) } + {joint_sphere} + put { scale( [J] + proximal_distal_ratio * ([I]+[K]) ) } + {segment} +} + +def finger_4 { + put { translate(joint_gap * joint_rad * [J]) + then rotate(middle_4_rot, [I]) + then translate((middle_ratio * distal_len + joint_gap * joint_rad) * [J]) } + {distal_4} + put { scale(proximal_distal_ratio) + then rotate(middle_4_rot / 2, [I]) + then translate((middle_ratio * distal_len + joint_gap * joint_rad) * [J]) } + {joint_sphere} + put { scale( middle_ratio * [J] + proximal_distal_ratio^2 * ([I]+[K]) ) } + {segment} +} + +% points on the palm of the hand +def proximal_0_loc (1.8,-5.5,0) +def proximal_1_loc (1.8,.1,0) +def proximal_2_loc (O) +def proximal_3_loc (-1.8,-.2,0) +def proximal_4_loc (-3.6,-.5,0) +def h5 (proximal_4_loc) + [-.6,-.2] +def h6 (h5) + [1,-5] +def h8 (proximal_0_loc) + [.75,-.5] +def h7 (h8) + [-.6,-.8] +def h6a (h6) + .6 * ((h7) - (h6)) +def h9 (h8) + [-1.9,1] +def h10 (proximal_1_loc) + [.85,-.3] + +def hand { + + % thumb has an extra rotation for opposable-ness! + def opposition_rot rotate(-50, [J]) + def thk_scale_0 1.2 + put { scale([thk_scale_0,.9,thk_scale_0]) % this distorts a little; oh well + then translate((joint_gap * joint_rad) * [J]) + then [[opposition_rot]] + then rotate(meta_0_rot, [I]) + then rotate(-spread_rot_0, [K]) + then translate((proximal_0_loc) - (O)) } + {finger_0} + + put { scale(thk_scale_0 * proximal_distal_ratio^2) + then [[opposition_rot]] + then rotate(meta_0_rot / 2, [I]) + then rotate(-spread_rot_0, [K]) + then translate((proximal_0_loc) - (O)) } + {joint_sphere} + + % index finger + def scale_1 .85 + put { scale(scale_1) + then translate((joint_gap * joint_rad) * [J]) + then rotate(meta_1_rot, [I]) + then rotate(-spread_rot, [K]) + then translate((proximal_1_loc) - (O)) } + {finger_1} + + put { scale(scale_1 * proximal_distal_ratio^2) + then rotate(meta_1_rot / 2, [I]) + then rotate(-spread_rot, [K]) + then translate((proximal_1_loc) - (O)) } + {joint_sphere} + + % middle finger + put { % no scale then + translate((joint_gap * joint_rad) * [J]) + then rotate(meta_2_rot, [I]) + % no spread rotation + then translate((proximal_2_loc) - (O)) } + {finger_2} + + put { scale(proximal_distal_ratio^2) + then rotate(meta_2_rot / 2, [I]) + then translate((proximal_2_loc) - (O)) } + {joint_sphere} + + % ring finger + def scale_3 .85 + put { scale(scale_3) + then translate((joint_gap * joint_rad) * [J]) + then rotate(meta_3_rot, [I]) + then rotate(spread_rot, [K]) + then translate((proximal_3_loc) - (O)) } + {finger_3} + + put { scale(scale_3 * proximal_distal_ratio^2) + then rotate(meta_3_rot / 2, [I]) + then rotate(spread_rot, [K]) + then translate((proximal_3_loc) - (O)) } + {joint_sphere} + + % little finger + def scale_4 .7 + put { scale(scale_4) + then translate((joint_gap * joint_rad) * [J]) + then rotate(meta_4_rot, [I]) + then rotate(2 * spread_rot, [K]) + then translate((proximal_4_loc) - (O)) } + {finger_4} + + put { scale(scale_4 * proximal_distal_ratio^2) + then rotate(meta_4_rot / 2, [I]) + then rotate(2 * spread_rot, [K]) + then translate((proximal_4_loc) - (O)) } + {joint_sphere} + + % palm is built by sweeping a polygon through a small + % angle in order to make it thicker at the wrist + put { translate(joint_gap * joint_rad * -[J]) } % drop polytope to expose knuckles + sweep { 1, rotate(6, (0,15,0), [I]) } + put { rotate(-3, (0,15,0), [I]) } { + % need two polygons for convexity; the desired shape is concave at the thumb + polygon(proximal_1_loc)(proximal_2_loc)(proximal_3_loc)(proximal_4_loc) + (h5)(h6)(h6a)(h9)(h10) + polygon(h6a)(h7)(h8)(h9) + } +} + +% a few views +def viewxf + <frontview> view((0,0,10)) + <sideview> view((10,0,0)) + <topview> view((0,10,0), (O), -[K]) + <> view((7,3,10)) + +% either a single copy or a repeat to show different angles +def scene + <repeated> + put { [[viewxf]] then scale(.25) } { + def N 4 + repeat { N, rotate(270/N, [3,2,1]), translate(14*[I]) } {hand} + } + <> put { [[viewxf]] then scale(.3) } {hand} + +{scene} |