commit 2afef8aa6b3043089c480f716f0ea8e5e11861b2
parent 22cbcbc08274cfcd9edbcd98c0ed1296cca9fbe4
Author: Egor Achkasov <eaachkasov@edu.hse.ru>
Date: Thu, 21 Nov 2024 14:56:25 +0100
Impl material loading
Diffstat:
| M | compute_paths.c | | | 182 | +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++---------------- |
1 file changed, 146 insertions(+), 36 deletions(-)
diff --git a/compute_paths.c b/compute_paths.c
@@ -22,16 +22,24 @@ typedef struct {
} Ray;
typedef struct {
+ char *name;
+ Vec3 reflectance;
+} Material;
+
+typedef struct {
Vec3 *vertices;
size_t num_vertices;
int32_t *indices;
size_t num_indices;
Vec3 *normals;
+ Material *material;
} Mesh;
typedef struct {
Mesh *meshes[256]; /* TODO: dynamic allocation, fix possible overflow */
size_t num_meshes;
+ Material *materials[256]; /* TODO: dynamic allocation, fix possible overflow */
+ size_t num_materials;
} Scene;
/* ==== VECTOR OPERATIONS ==== */
@@ -64,6 +72,53 @@ Vec3 vec3_scale(Vec3 a, float s)
/* ==== MESH LOADING ==== */
+/** Parse a Mitsuba XML "bsdf" node with a diffuse material.
+ * Extracts "rgb" property with "reflectance" name.
+ *
+ * \param node the xml node
+ * \param scene the scene to populate. Parsed material will be added to scene->materials.
+ */
+void parse_xmlnode_bsdf(IN xmlNodePtr node, OUT Scene *scene)
+{
+ char *material_name;
+ xmlChar *prop;
+ xmlNodePtr child, grandchild;
+
+ /* <bsdf type="diffuse" name="bsdf"> */
+ child = node->children;
+ while (child && child->type != XML_ELEMENT_NODE)
+ child = child->next;
+ if (!child) return;
+ if (xmlStrcmp(child->name, (const xmlChar *)"bsdf")
+ || xmlStrcmp(xmlGetProp(child, (const xmlChar *)"type"), (const xmlChar *)"diffuse"))
+ return;
+
+ /* <rgb value="0.603827 0.090842 0.049707" name="reflectance"/> */
+ grandchild = child->children;
+ while (grandchild && grandchild->type != XML_ELEMENT_NODE)
+ grandchild = grandchild->next;
+ if (!grandchild) return;
+ if (xmlStrcmp(grandchild->name, (const xmlChar *)"rgb")
+ || xmlStrcmp(xmlGetProp(grandchild, (const xmlChar *)"name"), (const xmlChar *)"reflectance"))
+ return;
+ prop = xmlGetProp(grandchild, (const xmlChar *)"value");
+ if (!prop) return;
+
+ /* Get the material name from the original node */
+ material_name = (char*)xmlGetProp(node, (const xmlChar *)"id");
+ if (!material_name) return;
+
+ /* Create the material object */
+ scene->materials[scene->num_materials] = (Material*)malloc(sizeof(Material));
+ scene->materials[scene->num_materials]->name = material_name;
+ sscanf((char*)prop, "%f %f %f",
+ &scene->materials[scene->num_materials]->reflectance.x,
+ &scene->materials[scene->num_materials]->reflectance.y,
+ &scene->materials[scene->num_materials]->reflectance.z);
+ xmlFree(prop);
+ ++scene->num_materials;
+}
+
/** Load a mesh from a PLY file.
*
* Supports only format binary_little_endian 1.0.
@@ -139,6 +194,74 @@ Mesh* load_mesh_ply(const char *mesh_filepath)
return mesh;
}
+/** Parse a Mitsuba XML "shape" node with a mesh.
+ * Assumes all the materials are already loaded in the scene.
+ *
+ * \param node the xml node
+ * \param dir the directory of the scene file
+ * \param scene_filepath the path to the scene file
+ * \param scene the scene to populate. Parsed mesh will be added to scene->meshes.
+ * \param material_name the name of the material
+ */
+void parse_xmlnode_shape(
+ IN xmlNodePtr node,
+ IN char* dir,
+ IN const char *scene_filepath,
+ OUT Scene *scene)
+{
+ xmlChar *prop;
+ xmlNodePtr child;
+ char *mesh_filepath = NULL;
+ char *material_name = NULL;
+
+ prop = xmlGetProp(node, (const xmlChar *)"type");
+ if (!prop || xmlStrcmp(prop, (const xmlChar *)"ply")) {
+ xmlFree(prop);
+ return NULL;
+ }
+ xmlFree(prop);
+ /* <shape type="ply" id="... found, now get the mesh */
+ for (child = node->children;
+ child && !(material_name && mesh_filepath);
+ child = child->next)
+ {
+ if (child->type != XML_ELEMENT_NODE)
+ continue;
+ /* get material name */
+ if (!xmlStrcmp(child->name, (const xmlChar *)"ref")) {
+ material_name = (char*)xmlGetProp(child, (const xmlChar *)"id");
+ continue;
+ }
+ /* get mesh filepath */
+ if (xmlStrcmp(child->name, (const xmlChar *)"string"))
+ continue;
+ prop = xmlGetProp(child, (const xmlChar *)"name");
+ if (!prop || xmlStrcmp(prop, (const xmlChar *)"filename"))
+ continue;
+ xmlFree(prop);
+ prop = xmlGetProp(child, (const xmlChar *)"value");
+ if (!prop) continue;
+ mesh_filepath = (char*)malloc(strlen(dir) + xmlStrlen(prop) + 2);
+ sprintf(mesh_filepath, "%s/%s", dir, prop);
+ }
+ if (!mesh_filepath || !material_name) return;
+
+ /* load the mesh */
+ scene->meshes[scene->num_meshes] = load_mesh_ply(mesh_filepath);
+ free(mesh_filepath);
+ xmlFree(prop);
+
+ /* Find the material */
+ for (size_t i = 0; i < scene->num_materials; ++i)
+ if (!strcmp(scene->materials[i]->name, material_name))
+ scene->meshes[scene->num_meshes]->material = scene->materials[i];
+ if (!scene->meshes[scene->num_meshes]->material) {
+ fprintf(stderr, "Material %s not found\n", material_name);
+ exit(8);
+ }
+ ++scene->num_meshes;
+}
+
/** Load a scene from a Mitsuba XML file.
*
* \param scene_filepath path to the Mitsuba XML file
@@ -146,51 +269,38 @@ Mesh* load_mesh_ply(const char *mesh_filepath)
*/
Scene load_scene(const char *scene_filepath)
{
- Scene scene;
+ Scene scene = {0};
+ xmlNodePtr root;
+ xmlNodePtr cur = NULL;
scene.num_meshes = 0;
- /* Parse xml file */
- xmlDocPtr doc = xmlReadFile(scene_filepath, NULL, 0);
+ /* Open the xml file */
+ xmlDocPtr doc = xmlReadFile(scene_filepath, NULL, XML_PARSE_NOBLANKS);
if (!doc) {
fprintf(stderr, "Could not parse file %s\n", scene_filepath);
exit(8);
}
- xmlNodePtr root = xmlDocGetRootElement(doc);
- xmlNodePtr cur = NULL;
- xmlNodePtr child = NULL;
- xmlChar *prop;
- char* dir = dirname((char*)scene_filepath);
- char *mesh_filepath;
+ root = xmlDocGetRootElement(doc);
+ if (!root) {
+ fprintf(stderr, "Could not get root element of %s\n", scene_filepath);
+ exit(8);
+ }
+
+ /* Get materials */
for (cur = root->children; cur; cur = cur->next) {
- if (cur->type != XML_ELEMENT_NODE
- || xmlStrcmp(cur->name, (const xmlChar *)"shape"))
+ if (cur->type != XML_ELEMENT_NODE)
continue;
- prop = xmlGetProp(cur, (const xmlChar *)"type");
- if (!prop || xmlStrcmp(prop, (const xmlChar *)"ply")) {
- xmlFree(prop);
+ if (!xmlStrcmp(cur->name, (const xmlChar *)"bsdf"))
+ parse_xmlnode_bsdf(cur, &scene);
+ }
+
+ /* Get shapes */
+ char* dir = dirname((char*)scene_filepath);
+ for (cur = root->children; cur; cur = cur->next) {
+ if (cur->type != XML_ELEMENT_NODE)
continue;
- }
- xmlFree(prop);
- /* <shape type="ply" id="... found, now get the mesh */
- for (child = cur->children; child; child = child->next) {
- if (child->type != XML_ELEMENT_NODE
- || xmlStrcmp(child->name, (const xmlChar *)"string"))
- continue;
- prop = xmlGetProp(child, (const xmlChar *)"name");
- if (!prop || xmlStrcmp(prop, (const xmlChar *)"filename"))
- continue;
- xmlFree(prop);
- prop = xmlGetProp(child, (const xmlChar *)"value");
- if (!prop) continue;
- /* get the mesh filepath */
- mesh_filepath = (char*)malloc(strlen(dir) + xmlStrlen(prop) + 2);
- sprintf(mesh_filepath, "%s/%s", dir, prop);
- /* load the mesh */
- scene.meshes[scene.num_meshes] = load_mesh_ply(mesh_filepath);
- ++scene.num_meshes;
- free(mesh_filepath);
- xmlFree(prop);
- }
+ if (!xmlStrcmp(cur->name, (const xmlChar *)"shape"))
+ parse_xmlnode_shape(cur, dir, scene_filepath, &scene);
}
return scene;
