I’m partial, but I like the Softimage soccer ball better than the Maya soccer ball.

The Softimage soccer ball is the one on the left. I took the ASS file for the soccer ball, did a few search and replace ops, and compiled my first procedural node. It’s pretty trivial, but it illustrates the basic framework. numNodes() returns the number of nodes you’re going to create; Arnold calls getNode() once for each node you create. I’m just creating one node, so I do it in getNode(), but you could also do it in init().

If you’re interested in learning more about the Arnold SDK and procedurals, you can download the SDK (docs included) at solidangle.com.

#include <ai.h>
#include <string.h>

static int init(AtNode *mynode, void **user_ptr )
{
  AiMsgInfo( "[soccer] -- greetings!" );
  return 1;
}

static int cleanup( void *d )
{
  return 1;
}

static int numNodes( void *d )
{
  return 1;
}

static AtNode *getNode( void *d, int index )
{

	AtByte nsides[540] = {
		4, 4, 4, 4, 4,
		// ...
		4, 4, 4, 4, 4};
  
	unsigned int vidxs[2160] = {
		292, 301, 12, 293, 302, 303, 304, 305, 302, 305, 306,
		//...
		169, 538, 537, 116, 168, 540, 539, 79, 151, 25, 541};

	unsigned int nidxs[2160] = {
		0, 1, 2, 3, 4, 5, 6, 7, 4, 7, 8, 9, 4, 9, 10, 11, 4, 
		// ...
		1211, 1216, 1215, 1230, 1229, 311, 322, 1231, 312};

	float vlist[1626] = {
		2.33102179f, 4.68985701f, -7.74118519f, -4.0108633f, -2.08138514f, 8.18039227f,
		//...
		1.70574367f, 2.03463793f, 9.00535202f, 2.94963598f, 0.0429565944f, 8.85224628f};

	float nlist[3696] = {
		-0.00219265698f, -0.443717808f, -0.896163881f, -0.112498537f, -0.405027777f, -0.907356858f, 
		//...
		-0.316353977f, -0.846433043f, 0.428335458f, 0.514008343f, -0.00765316607f, 0.857751012f};

	AtMatrix m;
	AiM4Identity( m );
	
	AtNode *n = AiNode( "polymesh" );
	AiNodeSetByte(n, "visibility", 255);
	AiNodeSetArray(n, "vlist",  AiArrayConvert(1626,  1, AI_TYPE_FLOAT, vlist));
	AiNodeSetArray(n, "nsides", AiArrayConvert(540,  1, AI_TYPE_BYTE,  nsides));
	AiNodeSetArray(n, "vidxs",  AiArrayConvert(2160,  1, AI_TYPE_UINT,  vidxs));
	AiNodeSetArray(n, "nlist",  AiArrayConvert(3696,  1, AI_TYPE_FLOAT, nlist));
	AiNodeSetArray(n, "nidxs",  AiArrayConvert(2160,  1, AI_TYPE_UINT,  vidxs));
//	AiNodeSetArray(n, "uvidxs", AiArrayConvert(384,  1, AI_TYPE_UINT,  uvidxs));
//	AiNodeSetArray(n, "uvlist", AiArrayConvert(270,  1, AI_TYPE_FLOAT, uvlist));

	AiNodeSetMatrix(n, "matrix", m );

	AiNodeSetStr(n, "name", "SISoccerBall");
	return n;
};



// --------------------------------------------------------------------------------
// dso hook.
// --------------------------------------------------------------------------------
proc_loader
{
  vtable->Init     = init;
  vtable->Cleanup  = cleanup;
  vtable->NumNodes = numNodes;
  vtable->GetNode  = getNode;
  strcpy_s(vtable->version, AI_VERSION);
  return 1;
}