Mercurial > forge
annotate extra/nurbs/inst/nrbcoons.m @ 12667:1411b4cf3c81 octave-forge
Check that the curves formed a closed surface
| author | rafavzqz |
|---|---|
| date | Tue, 28 Jul 2015 10:24:42 +0000 |
| parents | 37d08939bb7b |
| children |
| rev | line source |
|---|---|
| 5552 | 1 function srf = nrbcoons(u1, u2, v1, v2) |
| 2 % | |
| 3 % NRBCOONS: Construction of a Coons patch. | |
| 4 % | |
| 5 % Calling Sequence: | |
| 6 % | |
| 7 % srf = nrbcoons(ucrv1, ucrv2, vcrv1, vcrv2) | |
| 8 % | |
| 6910 | 9 % INPUT: |
| 5552 | 10 % |
| 6958 | 11 % ucrv1 : NURBS curve defining the bottom U direction boundary of |
| 5552 | 12 % the constructed NURBS surface. |
| 13 % | |
| 14 % ucrv2 : NURBS curve defining the top U direction boundary of | |
| 15 % the constructed NURBS surface. | |
| 16 % | |
| 17 % vcrv1 : NURBS curve defining the bottom V direction boundary of | |
| 18 % the constructed NURBS surface. | |
| 19 % | |
| 20 % vcrv2 : NURBS curve defining the top V direction boundary of | |
| 21 % the constructed NURBS surface. | |
| 6910 | 22 % |
| 23 % OUTPUT: | |
| 5552 | 24 % |
| 25 % srf : Coons NURBS surface patch. | |
| 26 % | |
| 27 % Description: | |
| 28 % | |
| 29 % Construction of a bilinearly blended Coons surface patch from four NURBS | |
| 30 % curves that define the boundary. | |
| 31 % | |
| 32 % The orientation of the four NURBS boundary curves. | |
| 33 % | |
| 34 % ^ V direction | |
| 35 % | | |
| 36 % | ucrv2 | |
| 37 % ------->-------- | |
| 38 % | | | |
| 39 % | | | |
| 40 % vcrv1 ^ Surface ^ vcrv2 | |
| 41 % | | | |
| 42 % | | | |
| 43 % ------->-----------> U direction | |
| 44 % ucrv1 | |
| 45 % | |
| 46 % | |
| 47 % Examples: | |
| 48 % | |
| 49 % // Define four NURBS curves and construct a Coons surface patch. | |
| 50 % pnts = [ 0.0 3.0 4.5 6.5 8.0 10.0; | |
| 51 % 0.0 0.0 0.0 0.0 0.0 0.0; | |
| 52 % 2.0 2.0 7.0 4.0 7.0 9.0]; | |
| 53 % crv1 = nrbmak(pnts, [0 0 0 1/3 0.5 2/3 1 1 1]); | |
| 54 % | |
| 55 % pnts= [ 0.0 3.0 5.0 8.0 10.0; | |
| 56 % 10.0 10.0 10.0 10.0 10.0; | |
| 57 % 3.0 5.0 8.0 6.0 10.0]; | |
| 58 % crv2 = nrbmak(pnts, [0 0 0 1/3 2/3 1 1 1]); | |
| 59 % | |
| 60 % pnts= [ 0.0 0.0 0.0 0.0; | |
| 61 % 0.0 3.0 8.0 10.0; | |
| 62 % 2.0 0.0 5.0 3.0]; | |
| 63 % crv3 = nrbmak(pnts, [0 0 0 0.5 1 1 1]); | |
| 64 % | |
| 65 % pnts= [ 10.0 10.0 10.0 10.0 10.0; | |
| 66 % 0.0 3.0 5.0 8.0 10.0; | |
| 67 % 9.0 7.0 7.0 10.0 10.0]; | |
| 68 % crv4 = nrbmak(pnts, [0 0 0 0.25 0.75 1 1 1]); | |
| 69 % | |
| 70 % srf = nrbcoons(crv1, crv2, crv3, crv4); | |
| 71 % nrbplot(srf,[20 20],220,45); | |
| 6910 | 72 % |
|
7919
27876b20006b
Spink's version of nrbcoons, the bug was in nrb4surf
rafavzqz
parents:
6958
diff
changeset
|
73 % Copyright (C) 2000 Mark Spink |
| 6910 | 74 % |
| 75 % This program is free software: you can redistribute it and/or modify | |
| 76 % it under the terms of the GNU General Public License as published by | |
| 11634 | 77 % the Free Software Foundation, either version 3 of the License, or |
| 6910 | 78 % (at your option) any later version. |
| 5552 | 79 |
| 6910 | 80 % This program is distributed in the hope that it will be useful, |
| 81 % but WITHOUT ANY WARRANTY; without even the implied warranty of | |
| 82 % MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
| 83 % GNU General Public License for more details. | |
| 84 % | |
| 85 % You should have received a copy of the GNU General Public License | |
| 86 % along with this program. If not, see <http://www.gnu.org/licenses/>. | |
| 5552 | 87 |
| 88 if nargin ~= 4 | |
| 89 error('Incorrect number of input arguments'); | |
| 90 end | |
| 91 | |
| 12667 | 92 if (max (abs (nrbeval (u1, u1.knots(1)) - nrbeval (v1, v1.knots(1)))) > 1e-10 || ... |
| 93 max (abs (nrbeval (u1, u1.knots(end)) - nrbeval (v2, v2.knots(1)))) > 1e-10 || ... | |
| 94 max (abs (nrbeval (u2, u2.knots(1)) - nrbeval (v1, v1.knots(end)))) > 1e-10 || ... | |
| 95 max (abs (nrbeval (u2, u2.knots(end)) - nrbeval (v2, v2.knots(end)))) > 1e-10) | |
| 96 error ('The four curves do not define a closed boundary') | |
| 97 end | |
| 98 | |
| 99 | |
| 100 | |
| 5552 | 101 r1 = nrbruled(u1, u2); |
| 102 r2 = nrbtransp(nrbruled(v1, v2)); | |
|
7919
27876b20006b
Spink's version of nrbcoons, the bug was in nrb4surf
rafavzqz
parents:
6958
diff
changeset
|
103 t = nrb4surf(u1.coefs(:,1), u1.coefs(:,end), u2.coefs(:,1), u2.coefs(:,end)); |
| 5552 | 104 |
| 105 % raise all surfaces to a common degree | |
| 106 du = max([r1.order(1), r2.order(1), t.order(1)]); | |
| 107 dv = max([r1.order(2), r2.order(2), t.order(2)]); | |
| 108 r1 = nrbdegelev(r1, [du - r1.order(1), dv - r1.order(2)]); | |
| 109 r2 = nrbdegelev(r2, [du - r2.order(1), dv - r2.order(2)]); | |
| 110 t = nrbdegelev(t, [du - t.order(1), dv - t.order(2)]); | |
| 111 | |
| 112 % merge the knot vectors, to obtain a common knot vector | |
| 113 | |
| 114 % U knots | |
| 115 k1 = r1.knots{1}; | |
| 116 k2 = r2.knots{1}; | |
| 117 k3 = t.knots{1}; | |
| 118 k = unique([k1 k2 k3]); | |
| 119 n = length(k); | |
| 120 kua = []; | |
| 121 kub = []; | |
| 122 kuc = []; | |
| 123 for i = 1:n | |
| 124 i1 = length(find(k1 == k(i))); | |
| 125 i2 = length(find(k2 == k(i))); | |
| 126 i3 = length(find(k3 == k(i))); | |
| 127 m = max([i1, i2, i3]); | |
| 128 kua = [kua k(i)*ones(1,m-i1)]; | |
| 129 kub = [kub k(i)*ones(1,m-i2)]; | |
| 130 kuc = [kuc k(i)*ones(1,m-i3)]; | |
| 131 end | |
| 132 | |
| 133 % V knots | |
| 134 k1 = r1.knots{2}; | |
| 135 k2 = r2.knots{2}; | |
| 136 k3 = t.knots{2}; | |
| 137 k = unique([k1 k2 k3]); | |
| 138 n = length(k); | |
| 139 kva = []; | |
| 140 kvb = []; | |
| 141 kvc = []; | |
| 142 for i = 1:n | |
| 143 i1 = length(find(k1 == k(i))); | |
| 144 i2 = length(find(k2 == k(i))); | |
| 145 i3 = length(find(k3 == k(i))); | |
| 146 m = max([i1, i2, i3]); | |
| 147 kva = [kva k(i)*ones(1,m-i1)]; | |
| 148 kvb = [kvb k(i)*ones(1,m-i2)]; | |
| 149 kvc = [kvc k(i)*ones(1,m-i3)]; | |
| 150 end | |
| 151 | |
| 152 r1 = nrbkntins(r1, {kua, kva}); | |
| 153 r2 = nrbkntins(r2, {kub, kvb}); | |
| 154 t = nrbkntins(t, {kuc, kvc}); | |
| 155 | |
| 156 % combine coefficient to construct Coons surface | |
| 157 coefs(1,:,:) = r1.coefs(1,:,:) + r2.coefs(1,:,:) - t.coefs(1,:,:); | |
| 158 coefs(2,:,:) = r1.coefs(2,:,:) + r2.coefs(2,:,:) - t.coefs(2,:,:); | |
| 159 coefs(3,:,:) = r1.coefs(3,:,:) + r2.coefs(3,:,:) - t.coefs(3,:,:); | |
| 160 coefs(4,:,:) = r1.coefs(4,:,:) + r2.coefs(4,:,:) - t.coefs(4,:,:); | |
| 161 srf = nrbmak(coefs, r1.knots); | |
| 162 | |
| 6910 | 163 end |
| 164 | |
| 165 %!demo | |
| 166 %! pnts = [ 0.0 3.0 4.5 6.5 8.0 10.0; | |
| 167 %! 0.0 0.0 0.0 0.0 0.0 0.0; | |
| 168 %! 2.0 2.0 7.0 4.0 7.0 9.0]; | |
| 169 %! crv1 = nrbmak(pnts, [0 0 0 1/3 0.5 2/3 1 1 1]); | |
| 170 %! | |
| 171 %! pnts= [ 0.0 3.0 5.0 8.0 10.0; | |
| 172 %! 10.0 10.0 10.0 10.0 10.0; | |
| 173 %! 3.0 5.0 8.0 6.0 10.0]; | |
| 174 %! crv2 = nrbmak(pnts, [0 0 0 1/3 2/3 1 1 1]); | |
| 175 %! | |
| 176 %! pnts= [ 0.0 0.0 0.0 0.0; | |
| 177 %! 0.0 3.0 8.0 10.0; | |
| 178 %! 2.0 0.0 5.0 3.0]; | |
| 179 %! crv3 = nrbmak(pnts, [0 0 0 0.5 1 1 1]); | |
| 180 %! | |
| 181 %! pnts= [ 10.0 10.0 10.0 10.0 10.0; | |
| 182 %! 0.0 3.0 5.0 8.0 10.0; | |
| 183 %! 9.0 7.0 7.0 10.0 10.0]; | |
| 184 %! crv4 = nrbmak(pnts, [0 0 0 0.25 0.75 1 1 1]); | |
| 185 %! | |
| 186 %! srf = nrbcoons(crv1, crv2, crv3, crv4); | |
| 187 %! | |
| 188 %! nrbplot(srf,[20 20]); | |
| 189 %! title('Construction of a bilinearly blended Coons surface.'); | |
|
7919
27876b20006b
Spink's version of nrbcoons, the bug was in nrb4surf
rafavzqz
parents:
6958
diff
changeset
|
190 %! hold off |