00001 """Python Module for building solid regular geometric objects.
00002
00003 Return value are list of vectors, 3 vectors define a facet.
00004
00005 Copyright (c) Berthold Grupp 2005
00006 License: LGPL
00007
00008 Sample code for creating a mesh:
00009 facets = Cube(3.0, 4.0, 5.0)
00010 m = Mesh.newMesh()
00011 m.addFacets(facets)
00012 """
00013
00014
00015 import math
00016
00017 def Sphere (radius, count):
00018 """Creates a sphere with a given radius.
00019
00020 bla bla bla
00021
00022 """
00023 return Ellipsoid(radius, radius, count)
00024
00025 def Ellipsoid (lenX, lenY, count):
00026 polyline = []
00027 step = math.pi / count
00028 i = 0.0
00029 while (i < math.pi + step / 10.0):
00030 x = math.cos(i) * lenX
00031 y = math.sin(i) * lenY
00032 polyline.append([x, y])
00033 i = i + step
00034
00035 return RotationBody(polyline, count)
00036
00037 def Cylinder (radius, len, closed, edgelen, count):
00038 return Cone(radius, radius, len, closed, edgelen, count)
00039
00040 def Cone (radius1, radius2, len, closed, edgelen, count):
00041 polyline = []
00042 if (closed):
00043 step = radius2 / math.ceil(radius2 / edgelen)
00044 i = 0.0
00045 while (i < radius2 - step / 2.0):
00046 polyline.append([len, i])
00047 i = i + step
00048
00049 ct = math.ceil(len / edgelen)
00050 step = len / ct
00051 rstep = (radius1 - radius2) / ct
00052 i = len;
00053 r = radius2
00054 while (i > 0.0 + step / 2.0):
00055 polyline.append([i, r])
00056 i = i - step
00057 r = r + rstep
00058 polyline.append([0.0, radius1])
00059
00060 if (closed):
00061 step = radius1 / math.ceil(radius1 / edgelen)
00062 i = radius1 - step
00063 while (i > 0.0 + step / 2.0):
00064 polyline.append([0.0, i])
00065 i = i - step
00066 polyline.append([0.0, 0.0])
00067
00068 return RotationBody(polyline, count)
00069
00070 def Toroid (radius1, radius2, count):
00071 polyline = []
00072
00073 step = math.pi * 2.0 / count
00074 i = -math.pi
00075 while (i < math.pi + step / 10.0):
00076 x = radius1 + math.cos(i) * radius2
00077 y = radius1 + math.sin(i) * radius2
00078 polyline.append([x, y])
00079 i = i + step
00080
00081 return RotationBody(polyline, count)
00082
00083
00084 def RotationBody (polyline, count):
00085 """Build a rotation body from a given (closed) polyline, rotation axis is the X-Axis.
00086
00087 Parameter: polyline: list of tuple of 2 floats (2d vector)
00088
00089 """
00090 facets = []
00091
00092 step = math.pi * 2.0 / count
00093 i = -math.pi;
00094 while (i < math.pi - step / 10.0):
00095 li = i + step
00096 for j in range(0, len(polyline) - 1):
00097 v1 = polyline[j]
00098 v2 = polyline[j+1]
00099
00100 x1 = v1[0]
00101 y1 = v1[1] * math.cos(i)
00102 z1 = v1[1] * math.sin(i)
00103 x2 = v2[0]
00104 y2 = v2[1] * math.cos(i)
00105 z2 = v2[1] * math.sin(i)
00106 x3 = v1[0]
00107 y3 = v1[1] * math.cos(li)
00108 z3 = v1[1] * math.sin(li)
00109 x4 = v2[0]
00110 y4 = v2[1] * math.cos(li)
00111 z4 = v2[1] * math.sin(li)
00112
00113 if (v1[1] != 0.0):
00114 facets.append([x1, y1, z1])
00115 facets.append([x2, y2, z2])
00116 facets.append([x3, y3, z3])
00117
00118 if (v2[1] != 0.0):
00119 facets.append([x2, y2, z2])
00120 facets.append([x4, y4, z4])
00121 facets.append([x3, y3, z3])
00122
00123 i = i + step
00124
00125 return facets;
00126
00127 def Cube (lenX, lenY, lenZ):
00128 hx = lenX / 2.0
00129 hy = lenY / 2.0
00130 hz = lenZ / 2.0
00131
00132 facets = []
00133
00134 facets.append([-hx, -hy, -hz])
00135 facets.append([hx, -hy, -hz])
00136 facets.append([hx, -hy, hz])
00137
00138 facets.append([-hx, -hy, -hz])
00139 facets.append([hx, -hy, hz])
00140 facets.append([-hx, -hy, hz])
00141
00142 facets.append([-hx, hy, -hz])
00143 facets.append([hx, hy, hz])
00144 facets.append([hx, hy, -hz])
00145
00146 facets.append([-hx, hy, -hz])
00147 facets.append([-hx, hy, hz])
00148 facets.append([hx, hy, hz])
00149
00150 facets.append([-hx, -hy, -hz])
00151 facets.append([-hx, hy, hz])
00152 facets.append([-hx, hy, -hz])
00153
00154 facets.append([-hx, -hy, -hz])
00155 facets.append([-hx, -hy, hz])
00156 facets.append([-hx, hy, hz])
00157
00158 facets.append([hx, -hy, -hz])
00159 facets.append([hx, hy, -hz])
00160 facets.append([hx, hy, hz])
00161
00162 facets.append([hx, -hy, -hz])
00163 facets.append([hx, hy, hz])
00164 facets.append([hx, -hy, hz])
00165
00166 facets.append([-hx, -hy, -hz])
00167 facets.append([-hx, hy, -hz])
00168 facets.append([hx, hy, -hz])
00169
00170 facets.append([-hx, -hy, -hz])
00171 facets.append([hx, hy, -hz])
00172 facets.append([hx, -hy, -hz])
00173
00174 facets.append([-hx, -hy, hz])
00175 facets.append([hx, hy, hz])
00176 facets.append([-hx, hy, hz])
00177
00178 facets.append([-hx, -hy, hz])
00179 facets.append([hx, -hy, hz])
00180 facets.append([hx, hy, hz])
00181
00182 return facets
00183
00184 def FineCube (lenX, lenY, lenZ, edgelen):
00185 hx = lenX / 2.0
00186 hy = lenY / 2.0
00187 hz = lenZ / 2.0
00188 cx = int(max(lenX / edgelen,1))
00189 dx = lenX / cx
00190 cy = int(max(lenY / edgelen,1))
00191 dy = lenY / cy
00192 cz = int(max(lenZ / edgelen,1))
00193 dz = lenZ / cz
00194
00195 facets = []
00196
00197
00198 for i in range(0,cx):
00199 for j in range(0,cy):
00200 facets.append([-hx+(i+0)*dx, -hy+(j+0)*dy, -hz])
00201 facets.append([-hx+(i+0)*dx, -hy+(j+1)*dy, -hz])
00202 facets.append([-hx+(i+1)*dx, -hy+(j+1)*dy, -hz])
00203
00204 facets.append([-hx+(i+0)*dx, -hy+(j+0)*dy, -hz])
00205 facets.append([-hx+(i+1)*dx, -hy+(j+1)*dy, -hz])
00206 facets.append([-hx+(i+1)*dx, -hy+(j+0)*dy, -hz])
00207
00208 facets.append([-hx+(i+0)*dx, -hy+(j+0)*dy, hz])
00209 facets.append([-hx+(i+1)*dx, -hy+(j+1)*dy, hz])
00210 facets.append([-hx+(i+0)*dx, -hy+(j+1)*dy, hz])
00211
00212 facets.append([-hx+(i+0)*dx, -hy+(j+0)*dy, hz])
00213 facets.append([-hx+(i+1)*dx, -hy+(j+0)*dy, hz])
00214 facets.append([-hx+(i+1)*dx, -hy+(j+1)*dy, hz])
00215
00216
00217 for i in range(0,cx):
00218 for j in range(0,cz):
00219 facets.append([-hx+(i+0)*dx, -hy, -hz+(j+0)*dz])
00220 facets.append([-hx+(i+1)*dx, -hy, -hz+(j+1)*dz])
00221 facets.append([-hx+(i+0)*dx, -hy, -hz+(j+1)*dz])
00222
00223 facets.append([-hx+(i+0)*dx, -hy, -hz+(j+0)*dz])
00224 facets.append([-hx+(i+1)*dx, -hy, -hz+(j+0)*dz])
00225 facets.append([-hx+(i+1)*dx, -hy, -hz+(j+1)*dz])
00226
00227 facets.append([-hx+(i+0)*dx, hy, -hz+(j+0)*dz])
00228 facets.append([-hx+(i+0)*dx, hy, -hz+(j+1)*dz])
00229 facets.append([-hx+(i+1)*dx, hy, -hz+(j+1)*dz])
00230
00231 facets.append([-hx+(i+0)*dx, hy, -hz+(j+0)*dz])
00232 facets.append([-hx+(i+1)*dx, hy, -hz+(j+1)*dz])
00233 facets.append([-hx+(i+1)*dx, hy, -hz+(j+0)*dz])
00234
00235
00236 for i in range(0,cy):
00237 for j in range(0,cz):
00238 facets.append([-hx, -hy+(i+0)*dy, -hz+(j+0)*dz])
00239 facets.append([-hx, -hy+(i+0)*dy, -hz+(j+1)*dz])
00240 facets.append([-hx, -hy+(i+1)*dy, -hz+(j+1)*dz])
00241
00242 facets.append([-hx, -hy+(i+0)*dy, -hz+(j+0)*dz])
00243 facets.append([-hx, -hy+(i+1)*dy, -hz+(j+1)*dz])
00244 facets.append([-hx, -hy+(i+1)*dy, -hz+(j+0)*dz])
00245
00246 facets.append([hx, -hy+(i+0)*dy, -hz+(j+0)*dz])
00247 facets.append([hx, -hy+(i+1)*dy, -hz+(j+1)*dz])
00248 facets.append([hx, -hy+(i+0)*dy, -hz+(j+1)*dz])
00249
00250 facets.append([hx, -hy+(i+0)*dy, -hz+(j+0)*dz])
00251 facets.append([hx, -hy+(i+1)*dy, -hz+(j+0)*dz])
00252 facets.append([hx, -hy+(i+1)*dy, -hz+(j+1)*dz])
00253
00254 return facets
00255
00256 def main ():
00257 Cylinder (10.0, 20.0, 1, 10, 10)
00258
00259 if __name__ == "__main__":
00260 main()
00261
