[pstricks] pst-solides3d psSurface

[Leon Free]

hi
i'd like to use the projection+intersection facilities included in
pst-solides3d. i started plotting a 3d function z=f(x,y) (see attached
tex source).

while \psplotThreeD from pst-3dplot works fine, the \psSurface macro
from pst-solides3d fails.

latex+dvips does not complain but when trying to view the postscript,
ghostscript says:

Error: /undefinedresult in --div--
Operand stack:
   --nostringval--   dy   0   0
Execution stack:
   %interp_exit   .runexec2   --nostringval--   --nostringval--
--nostringval--   2   %stopped_push   --nostringval--   --nostringval--
  --nostringval--   false   1   %stopped_push   1878   1   3
%oparray_pop   1877   1   3   %oparray_pop   1861   1   3   %oparray_pop
  1755   1   3   %oparray_pop   --nostringval--   %errorexec_pop
.runexec2   --nostringval--   --nostringval--   --nostringval--   2
%stopped_push   --nostringval--   --nostringval--   --nostringval--
Dictionary stack:
   --dict:1157/1684(ro)(G)--   --dict:0/20(G)--   --dict:83/200(L)--
--dict:745/1012(L)--   --dict:176/300(L)--   --dict:38/200(L)--
--dict:197/200(L)--   --dict:745/1012(L)--   --dict:8/10(L)--
Current allocation mode is local
Last OS error: 2
GPL Ghostscript 8.71: Unrecoverable error, exit code 1

the ps2pdf utility issues the same message with the further information
that: Current file position is 455474

all i can guess is that a ./0 division occurs at some point. but i cant
debug it further. does anybody know what's wrong ?
lf


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