### Other attribute on param section

Other attributes that you may encounter in the param section are:

render

is the type of output. The allowed values are : "raytracing" ( standard ), "depth", "vrml", "t_analysis", "preview".

"raytracing" is the standard output.

"vrml" outputs a .wrl file. It is in VRML 1.0 file format. You can see it with a VRML browser.

"t_analysis" outputs a .ana file. It describes some characteristics of the objects in the scene.

"preview" outputs a .bmp file. It is a preview image of the scene.

toll

is a value used in intersection calculus. Intersection is true if the distance is less then toll. This avoid the noise. If in your image you get some noise you may change this.

anti_al_toll

if it is low RT makes a more in depth analysis for antialiasing.

ambientcolor

is the ambient lamp color. Default is (1,1,1). You don' t need to change this.

backcolor

color of the background. The default is (0,0,0).

ambient_ni

value for refraction coefficient of the vacuum. Default is 1.