2. Preparation

You decided to implement a new custom object? Fine, here is what to do first:

• Pick a short, pregnant, descriptive, non colliding name for your object type. To avoid clashes, I suggest to precede the name with the initials of the author (yours) as it is tradition with RenderMan shaders.
• Copy "csphere.c" and "csphere.tcl" to "yourname.c" and "yourname.tcl" respectively.
• Rename all occurences of csphere in those files to yourname.
• Edit the struct that holds the parameters of your object. This struct will be referred to later as the custom object.

Here is the corresponding code snippet from the csphere example:

#include "ayam.h"

/* csphere.c - csphere custom object */

static char *csphere_name = "CSphere";

static unsigned int csphere_id;

typedef struct csphere_object_s
{
  char closed;
  char is_simple;
  double radius;
  double zmin, zmax;
  double thetamax;
} csphere_object;

Now you are ready to adapt the implementation of some functions as they are described in the next sections of the manual.