I quickly searched the newsgroups for this, but didn't find anything.  Is 
it a known bug that the normal returned by trace() for a text object is 
reversed?

Quick example:
// ---- START ----
// Blue lines are traces from x=0 towards the objects
// Red lines are the normals returned by trace()
// reference sphere works as expected
// text doesn't
#version 3.5;

global_settings {
  assumed_gamma 1.0
}
default { texture { 
  pigment { color rgbt <1,1,1,0.5> }
  finish { specular 0 roughness 1 } } }
camera { location  <0, 0, -3> }
light_source { <-2,2,-4> color rgb 1 }

#declare Sphere = sphere { 0, 0.5
  translate <-1,0,0>
}
Sphere

#declare Text = text {
  ttf "arial.ttf" "O" 1, <0,0,0>
  scale 2
  translate <0.5,-0.75,-0.5>
}
Text

cylinder { <0,-2,0>, <0,2,0>, 0.025 }
cylinder { <-2,0.2,0>, <0,0.2,0>, 0.025 pigment { color rgb <0,0,1> } }
cylinder { <0,-0.2,0>, <2,-0.2,0>, 0.025 pigment { color rgb <0,0,1> } }

#declare TN = <0,0,0>;
#declare TH = trace(Sphere,<0,0.2,0>,-x,TN);
cylinder { TH, TH+TN, 0.025 pigment { color rgb <1,0,0> } }

#declare TH = trace(Text,<0,-0.2,0>,x,TN);
cylinder { TH, TH+TN, 0.025 pigment { color rgb <1,0,0> } }
// ---- END ----

Post a reply to this message