[Radiance-general] smooth on meshes

[Gregory J. Ward]

Hi Ignacio,

Because the normal smoothing doesn't affect the underlying geometry,  
side shading such as shown in your image can exhibit unexpected  
behavior, where the actual shape of the surfaces determines the  
shadows.  Some scanline-based renderers are able to compensate for  
this with specialized algorithms, but it's almost impossible to avoid  
in a ray-tracing system.  You need to create a finer mesh to  
ameliorate the problem, though you'll never be able to eliminate it  
entirely.  The only way to do that is to have the correct geometry to  
begin with -- i.e., by using a sphere in this case.

-Greg

> From: Ignacio Munarriz <info at aisarquitectura.com>
> Date: May 25, 2007 12:47:59 PM PDT
>
> Hi all, i'm enjoying wit a 3dsmax2mesh converter, but i've got some  
> problems in the second stage (first stage vertexs, second stage  
> normals), i've got obj2mesh as reference and using cvtri function  
> to create the mesh faces , but an artifact has appeared in the  
> contour line between light and shadow in some objects like spheres  
> as in www.aisarquitectura.com/img/sphere.jpg , i think i've seen  
> something similar before in radiance docs or list, but now i dont  
> remember where, any help?