[Radiance-general] obj2rad splitting planar surfaces?

[Randolph M. Fritz]

Thank you very much.  It does matter--these surfaces are going to be 
used by mkillum.  Using -f fixes the problem, and here I am embarassed 
that I didn't figure it out in the first place.

Oh, well.  At least I learned a bit more about debugging Radiance.

Randolph

On 2012-03-22 19:12:49 +0000, Greg Ward said:

> Hi Randolph,
> 
> Seems obj2rad has an initial test to determine if a polygon has 
> specified normals.  If it does, then it breaks it into triangles.  Once 
> it looks at the triangles, it then sees if the normals actually require 
> interpolation or not.  If they don't, then it doesn't specify a 
> texture, but they still get output as triangles.
> 
> Is it a problem?  Just take off the normals if it is.
> 
> Best,
> -Greg
> 
>> From: "Randolph M. Fritz" <RFritz at lbl.gov>
>> Date: March 22, 2012 11:14:31 AM PDT
>> 
>> Am I missing something?  It looks like obj2rad is splitting a planar 
>> rectangle into two triangles.
>> 
>> I think this OBJ file describes a single vertical rectangle:
>> -----------------------
>> # Rhino
>> 
>> mtllib one_plane.mtl
>> g IllumSrc__Center
>> o FirstIllum
>> usemtl Default
>> v 81.44685363769531 1 42
>> v 81.44685363769531 1 90
>> v 35.44684982299805 1 42
>> v 35.44684982299805 1 90
>> vt 0 0
>> vt 0 1
>> vt 1 0
>> vt 1 1
>> vn 0 1 0
>> vn 0 1 0
>> vn 0 1 0
>> vn 0 1 0
>> f 4/4/4 2/2/2 1/1/1 3/3/3
>> -----------------------
>> 
>> And this obj2rad file describes two triangles:
>> -----------------------
>> # obj2rad one_plane.obj
>> # Rhino
>> 
>> Default polygon FirstIllum.1
>> 0
>> 0
>> 9
>> 35.446849823                  1                 90
>> 81.4468536377                  1                 90
>> 81.4468536377                  1                 42
>> 
>> Default polygon FirstIllum.1
>> 0
>> 0
>> 9
>> 81.4468536377                  1                 42
>> 35.446849823                  1                 42
>> 35.446849823                  1                 90
>> 
>> # Done processing file: one_plane.obj
>> # 19 lines, 18 statements, 1 unrecognized
>> -----------------------
>> 
>> 
>> Meantime, I'd better come up with a script that produces the proper output.
>> --
>> Randolph M. Fritz


-- 
Randolph M. Fritz