Converts Nokia 3D models to DAE models (http://maps3d.svc.nokia.com/webgl/index.html)

n3mtodae.c

#include <sys/stat.h>
#include <sys/mman.h>
#include <fcntl.h>
#include <unistd.h>
#include <stdlib.h>
#include <stdio.h>

struct xyz
{
	float x, y, z;
};

struct uv
{
	float u, v;
};

struct triangle
{
	unsigned short a, b, c;
};

struct source
{
	int number_of_verts;
	
	struct xyz *xyz_coords;
	struct uv *uv_coords;
};

struct material
{
	int number_of_tris;
	int source_index;
	
	struct triangle *tris;
};

struct model
{
	int bucket_levels;
	int number_of_sources;
	int number_of_materials;
	
	struct source *sources;
	struct material *materials;
};

int open_n3m (struct model *m, void *data)
{
	char *magic = (char*)data;
	printf("magic: %c%c%c\n", magic[0], magic[1], magic[2]);
	if (magic[0] != 'N' || magic[1] != '3' || magic[2] != 'M') {
		return -1;
	}
	
	char version = magic[3];
	printf("version: %c\n", version);
	
	int *header = (int*)data;
	m->number_of_sources = header[1];
	m->number_of_materials = header[2];
	printf("number_of_sources: %d\n", m->number_of_sources);
	printf("number_of_materials: %d\n", m->number_of_materials);
	
	m->sources = calloc(m->number_of_sources, sizeof(struct source));
	m->materials = calloc(m->number_of_materials, sizeof(struct material));
	
	int i = 0;
	for (i = 0; i < m->number_of_sources; i++) {
		struct source *s = &m->sources[i];
		
		int offset = i * 2 + 3;
		
		int data_offset = header[offset];
		s->number_of_verts = header[offset + 1];
		
		printf("data_offset: %d\n", data_offset);
		printf("source[%d].number_of_verts: %d\n", i, s->number_of_verts);
		
		s->xyz_coords = (struct xyz*)((char*)data + data_offset);
		s->uv_coords = (struct uv*)((char*)data + data_offset + s->number_of_verts * 12);
	}
	
	for (i = 0; i < m->number_of_materials; i++) {
		struct material *mat = &m->materials[i];
		
		int offset = m->number_of_sources * 2 + i * 4 + 3;
		
		int indices_offset = header[offset];
		
		mat->number_of_tris = header[offset + 1];		
		mat->source_index = header[offset + 2];
		mat->tris = (struct triangle*)((char*)data + indices_offset);
		
		printf("material[%d].number_of_tris: %d\n", i, mat->number_of_tris);
		printf("material[%d].source_index: %d\n", i, mat->source_index);
	}
	
	return 0;
}

int save_dae (struct model *m, FILE *f)
{
	fprintf(f, "<?xml version=\"1.0\" encoding=\"UTF-8\" standalone=\"no\" ?>\n");
	fprintf(f, "<COLLADA xmlns=\"http://www.collada.org/2005/11/COLLADASchema\" version=\"1.4.1\">\n");
	fprintf(f, "    <asset>\n");
	fprintf(f, "        <contributor>\n");
	fprintf(f, "            <authoring_tool>n3mtodae</authoring_tool>\n");
	fprintf(f, "        </contributor>\n");
	fprintf(f, "        <created>2012-01-21T04:10:34Z</created>\n");
	fprintf(f, "        <modified>2012-01-21T04:10:34Z</modified>\n");
	fprintf(f, "        <unit meter=\"0.0254000\" name=\"inch\" />\n");
	fprintf(f, "        <up_axis>X_UP</up_axis>\n");
	fprintf(f, "    </asset>\n");
	
	fprintf(f, "    <library_visual_scenes>\n");
	fprintf(f, "        <visual_scene id=\"ID1VISUALSCENE\">\n");
	fprintf(f, "            <node name=\"n3mtodae\">\n");
	int i = 0;
	for (i = 0; i < m->number_of_materials; i++) {
		struct material *mat = &m->materials[i];

		fprintf(f, "                <instance_geometry url=\"#ID%pGEOMETRY\">\n", mat);
		
		fprintf(f, "                    <bind_material>\n");
        fprintf(f, "                        <technique_common>\n");
        fprintf(f, "                            <instance_material symbol=\"Material2\" target=\"#ID4\">\n");
		fprintf(f, "                                <bind_vertex_input semantic=\"UVSET0\" input_semantic=\"TEXCOORD\" input_set=\"0\" />\n");
        fprintf(f, "                            </instance_material>\n");
        fprintf(f, "                        </technique_common>\n");
		fprintf(f, "                    </bind_material>\n");
		
		fprintf(f, "                </instance_geometry>\n");
	}
	fprintf(f, "            </node>\n");
	fprintf(f, "        </visual_scene>\n");
	fprintf(f, "    </library_visual_scenes>\n");
	
	fprintf(f, "    <library_geometries>\n");
	for (i = 0; i < m->number_of_materials; i++) {
		struct material *mat = &m->materials[i];
		struct source *src = &m->sources[mat->source_index];
		
		fprintf(f, "        <geometry id=\"ID%pGEOMETRY\">\n", mat);
		fprintf(f, "            <mesh>\n");
		
		fprintf(f, "                <source id=\"ID%pSOURCE\">\n", src->xyz_coords);
		fprintf(f, "                    <float_array id=\"ID%pARRAY\" count=\"%d\">", src->xyz_coords, src->number_of_verts * 3);
		int j = 0;
		for (j = 0; j < src->number_of_verts; j++) {
			fprintf(f, "%g %g %g ", src->xyz_coords[j].x, src->xyz_coords[j].y, src->xyz_coords[j].z);
		}
		fprintf(f, "</float_array>\n");
		fprintf(f, "                    <technique_common>\n");
        fprintf(f, "                        <accessor count=\"%d\" source=\"#ID%pARRAY\" stride=\"3\">\n", src->number_of_verts, src->xyz_coords);
        fprintf(f, "                            <param name=\"X\" type=\"float\" />\n");
        fprintf(f, "                            <param name=\"Y\" type=\"float\" />\n");
        fprintf(f, "                            <param name=\"Z\" type=\"float\" />\n");
        fprintf(f, "                        </accessor>\n");
        fprintf(f, "                    </technique_common>\n");
		fprintf(f, "                </source>\n");
		
		fprintf(f, "                <vertices id=\"ID%pVERTICES\">\n", mat);
        fprintf(f, "                    <input semantic=\"POSITION\" source=\"#ID%pSOURCE\" />\n", src->xyz_coords);
        fprintf(f, "                </vertices>\n");

		fprintf(f, "                <triangles count=\"%d\" material=\"Material2\">\n", mat->number_of_tris);
        fprintf(f, "                    <input offset=\"0\" semantic=\"VERTEX\" source=\"#ID%pVERTICES\" />\n", mat);
        fprintf(f, "                    <p>");

		for (j = 0; j < mat->number_of_tris; j++) {
			fprintf(f, "%d %d %d ", mat->tris[j].a, mat->tris[j].b, mat->tris[j].c);
		}

		fprintf(f, "</p>\n");
		fprintf(f, "                </triangles>\n");
		
		fprintf(f, "            </mesh>\n");
		fprintf(f, "        </geometry>\n");
	}
	fprintf(f, "    </library_geometries>\n");
	
	fprintf(f, "    <library_materials>\n");
    fprintf(f, "        <material id=\"ID4\" name=\"material\">\n");
    fprintf(f, "            <instance_effect url=\"#ID3\" />\n");
    fprintf(f, "        </material>\n");
	fprintf(f, "    </library_materials>\n");
	
	fprintf(f, "    <library_effects>\n");
    fprintf(f, "        <effect id=\"ID3\">\n");
    fprintf(f, "            <profile_COMMON>\n");
    fprintf(f, "                <technique sid=\"COMMON\">\n");
    fprintf(f, "                    <lambert>\n");
    fprintf(f, "                        <diffuse>\n");
    fprintf(f, "                            <color>1.0000000 1.0000000 1.0000000 1.0000000</color>\n");
    fprintf(f, "                        </diffuse>\n");
    fprintf(f, "                    </lambert>\n");
    fprintf(f, "                </technique>\n");
    fprintf(f, "            </profile_COMMON>\n");
    fprintf(f, "        </effect>\n");
    fprintf(f, "    </library_effects>\n");
	
	fprintf(f, "    <scene>\n");
	fprintf(f, "        <instance_visual_scene url=\"#ID1VISUALSCENE\" />\n");
	fprintf(f, "    </scene>\n");
	
	fprintf(f, "</COLLADA>\n");
	
	return 0;
}

int main()
{
	int fd = open("/Users/fak/Desktop/Nokia3D/b.n3m", O_RDONLY);
	struct stat sb = {0};
	fstat(fd, &sb);
	
	void *data = mmap(0, sb.st_size, PROT_READ, MAP_SHARED, fd, 0);
	
	struct model m;
	
	open_n3m (&m, data);

	FILE *out = fopen("/Users/fak/Desktop/Nokia3D/b.dae", "w");
	save_dae (&m, out);
	
	return 0;
}