From 45d3b227822064d95d870d45c0aca7bc3d2340cc Mon Sep 17 00:00:00 2001 From: Paul Melis Date: Tue, 4 Jun 2024 15:31:21 +0200 Subject: [PATCH] Initial work to correctly handle the node hierarchy in a glTF file. Static meshes seem to work fine in my tests. Haven't tried anything animated yet, but it's almost certainly broken. --- src/rmodels.c | 114 ++++++++++++++++++++++++++++++++++++++++---------- 1 file changed, 91 insertions(+), 23 deletions(-) diff --git a/src/rmodels.c b/src/rmodels.c index 249201513..4305a95fc 100644 --- a/src/rmodels.c +++ b/src/rmodels.c @@ -4885,6 +4885,7 @@ static Model LoadGLTF(const char *fileName) /********************************************************************************************* Function implemented by Wilhem Barbier(@wbrbr), with modifications by Tyler Bezera(@gamerfiend) + Transform handling implemented by Paul Melis (@paulmelis). Reviewed by Ramon Santamaria (@raysan5) FEATURES: @@ -4894,6 +4895,9 @@ static Model LoadGLTF(const char *fileName) PBR specular/glossiness flow and extended texture flows not supported - Supports multiple meshes per model (every primitives is loaded as a separate mesh) - Supports basic animations + - Node hierarchy and mesh transforms are applied, but the hierarchy is flattened. + - Mesh instances in the glTF file (i.e. same mesh linked from multiple nodes) + are turned into separate raylib Meshes. RESTRICTIONS: - Only triangle meshes supported @@ -4903,7 +4907,6 @@ static Model LoadGLTF(const char *fileName) > Texcoords: vec2: float > Colors: vec4: u8, u16, f32 (normalized) > Indices: u16, u32 (truncated to u16) - - Node hierarchies or transforms not supported ***********************************************************************************************/ @@ -4955,8 +4958,17 @@ static Model LoadGLTF(const char *fileName) if (result != cgltf_result_success) TRACELOG(LOG_INFO, "MODEL: [%s] Failed to load mesh/material buffers", fileName); int primitivesCount = 0; - // NOTE: We will load every primitive in the glTF as a separate raylib mesh - for (unsigned int i = 0; i < data->meshes_count; i++) primitivesCount += (int)data->meshes[i].primitives_count; + // NOTE: We will load every primitive in the glTF as a separate raylib Mesh. + // Determine total number of meshes needed from the node hierarchy. + for (unsigned int i = 0; i < data->nodes_count; i++) + { + cgltf_node *node = &(data->nodes[i]); + cgltf_mesh *mesh = node->mesh; + if (!mesh) + continue; + primitivesCount += mesh->primitives_count; + } + TRACELOG(LOG_DEBUG, " > Primitives count based on hierarchy: %i", primitivesCount); // Load our model data: meshes and materials model.meshCount = primitivesCount; @@ -5059,27 +5071,51 @@ static Model LoadGLTF(const char *fileName) // has_clearcoat, has_transmission, has_volume, has_ior, has specular, has_sheen } - // Load meshes data + // Visit each node in the hierarchy and process any mesh linked from it. + // Each primitive within a glTF node becomes a Raylib Mesh. + // The local-to-world transform of each node is used to transform the + // points/normals/tangents of the created Mesh(es). + // Any glTF mesh linked from more than one Node (i.e. instancing) + // is turned into multiple Mesh's, as each Node will have its own + // transform applied. + // Note: the code below disregards the scenes defined in the file, all nodes are used. //---------------------------------------------------------------------------------------------------- - for (unsigned int i = 0, meshIndex = 0; i < data->meshes_count; i++) + int meshIndex = 0; + for (unsigned int i = 0; i < data->nodes_count; i++) { - // NOTE: meshIndex accumulates primitives + cgltf_node *node = &(data->nodes[i]); - for (unsigned int p = 0; p < data->meshes[i].primitives_count; p++) + cgltf_mesh *mesh = node->mesh; + if (!mesh) + continue; + + cgltf_float world_transform[16]; + cgltf_node_transform_world(node, world_transform); + + Matrix world_matrix = { + world_transform[0], world_transform[4], world_transform[8], world_transform[12], + world_transform[1], world_transform[5], world_transform[9], world_transform[13], + world_transform[2], world_transform[6], world_transform[10], world_transform[14], + world_transform[3], world_transform[7], world_transform[11], world_transform[15] + }; + + Matrix world_matrix_normals = MatrixTranspose(MatrixInvert(world_matrix)); + + for (unsigned int p = 0; p < mesh->primitives_count; p++) { // NOTE: We only support primitives defined by triangles // Other alternatives: points, lines, line_strip, triangle_strip - if (data->meshes[i].primitives[p].type != cgltf_primitive_type_triangles) continue; + if (mesh->primitives[p].type != cgltf_primitive_type_triangles) continue; // NOTE: Attributes data could be provided in several data formats (8, 8u, 16u, 32...), // Only some formats for each attribute type are supported, read info at the top of this function! - for (unsigned int j = 0; j < data->meshes[i].primitives[p].attributes_count; j++) + for (unsigned int j = 0; j < mesh->primitives[p].attributes_count; j++) { // Check the different attributes for every primitive - if (data->meshes[i].primitives[p].attributes[j].type == cgltf_attribute_type_position) // POSITION, vec3, float + if (mesh->primitives[p].attributes[j].type == cgltf_attribute_type_position) // POSITION, vec3, float { - cgltf_accessor *attribute = data->meshes[i].primitives[p].attributes[j].data; + cgltf_accessor *attribute = mesh->primitives[p].attributes[j].data; // WARNING: SPECS: POSITION accessor MUST have its min and max properties defined @@ -5091,12 +5127,22 @@ static Model LoadGLTF(const char *fileName) // Load 3 components of float data type into mesh.vertices LOAD_ATTRIBUTE(attribute, 3, float, model.meshes[meshIndex].vertices) + + // Transform the vertices + float *vertices = model.meshes[meshIndex].vertices; + for (int k = 0; k < attribute->count; k++) + { + Vector3 vt = Vector3Transform((Vector3){ vertices[3*k], vertices[3*k+1], vertices[3*k+2] }, world_matrix); + vertices[3*k] = vt.x; + vertices[3*k+1] = vt.y; + vertices[3*k+2] = vt.z; + } } else TRACELOG(LOG_WARNING, "MODEL: [%s] Vertices attribute data format not supported, use vec3 float", fileName); } - else if (data->meshes[i].primitives[p].attributes[j].type == cgltf_attribute_type_normal) // NORMAL, vec3, float + else if (mesh->primitives[p].attributes[j].type == cgltf_attribute_type_normal) // NORMAL, vec3, float { - cgltf_accessor *attribute = data->meshes[i].primitives[p].attributes[j].data; + cgltf_accessor *attribute = mesh->primitives[p].attributes[j].data; if ((attribute->type == cgltf_type_vec3) && (attribute->component_type == cgltf_component_type_r_32f)) { @@ -5105,12 +5151,22 @@ static Model LoadGLTF(const char *fileName) // Load 3 components of float data type into mesh.normals LOAD_ATTRIBUTE(attribute, 3, float, model.meshes[meshIndex].normals) + + // Transform the normals + float *normals = model.meshes[meshIndex].normals; + for (int k = 0; k < attribute->count; k++) + { + Vector3 nt = Vector3Transform((Vector3){ normals[3*k], normals[3*k+1], normals[3*k+2] }, world_matrix_normals); + normals[3*k] = nt.x; + normals[3*k+1] = nt.y; + normals[3*k+2] = nt.z; + } } else TRACELOG(LOG_WARNING, "MODEL: [%s] Normal attribute data format not supported, use vec3 float", fileName); } - else if (data->meshes[i].primitives[p].attributes[j].type == cgltf_attribute_type_tangent) // TANGENT, vec3, float + else if (mesh->primitives[p].attributes[j].type == cgltf_attribute_type_tangent) // TANGENT, vec3, float { - cgltf_accessor *attribute = data->meshes[i].primitives[p].attributes[j].data; + cgltf_accessor *attribute = mesh->primitives[p].attributes[j].data; if ((attribute->type == cgltf_type_vec4) && (attribute->component_type == cgltf_component_type_r_32f)) { @@ -5119,15 +5175,25 @@ static Model LoadGLTF(const char *fileName) // Load 4 components of float data type into mesh.tangents LOAD_ATTRIBUTE(attribute, 4, float, model.meshes[meshIndex].tangents) + + // Transform the tangents + float *tangents = model.meshes[meshIndex].tangents; + for (int k = 0; k < attribute->count; k++) + { + Vector3 tt = Vector3Transform((Vector3){ tangents[3*k], tangents[3*k+1], tangents[3*k+2] }, world_matrix); + tangents[3*k] = tt.x; + tangents[3*k+1] = tt.y; + tangents[3*k+2] = tt.z; + } } else TRACELOG(LOG_WARNING, "MODEL: [%s] Tangent attribute data format not supported, use vec4 float", fileName); } - else if (data->meshes[i].primitives[p].attributes[j].type == cgltf_attribute_type_texcoord) // TEXCOORD_n, vec2, float/u8n/u16n + else if (mesh->primitives[p].attributes[j].type == cgltf_attribute_type_texcoord) // TEXCOORD_n, vec2, float/u8n/u16n { // Support up to 2 texture coordinates attributes float *texcoordPtr = NULL; - cgltf_accessor *attribute = data->meshes[i].primitives[p].attributes[j].data; + cgltf_accessor *attribute = mesh->primitives[p].attributes[j].data; if (attribute->type == cgltf_type_vec2) { @@ -5171,7 +5237,7 @@ static Model LoadGLTF(const char *fileName) } else TRACELOG(LOG_WARNING, "MODEL: [%s] Texcoords attribute data format not supported, use vec2 float", fileName); - int index = data->meshes[i].primitives[p].attributes[j].index; + int index = mesh->primitives[p].attributes[j].index; if (index == 0) model.meshes[meshIndex].texcoords = texcoordPtr; else if (index == 1) model.meshes[meshIndex].texcoords2 = texcoordPtr; else @@ -5180,9 +5246,9 @@ static Model LoadGLTF(const char *fileName) if (texcoordPtr != NULL) RL_FREE(texcoordPtr); } } - else if (data->meshes[i].primitives[p].attributes[j].type == cgltf_attribute_type_color) // COLOR_n, vec3/vec4, float/u8n/u16n + else if (mesh->primitives[p].attributes[j].type == cgltf_attribute_type_color) // COLOR_n, vec3/vec4, float/u8n/u16n { - cgltf_accessor *attribute = data->meshes[i].primitives[p].attributes[j].data; + cgltf_accessor *attribute = mesh->primitives[p].attributes[j].data; // WARNING: SPECS: All components of each COLOR_n accessor element MUST be clamped to [0.0, 1.0] range @@ -5299,9 +5365,9 @@ static Model LoadGLTF(const char *fileName) } // Load primitive indices data (if provided) - if (data->meshes[i].primitives[p].indices != NULL) + if (mesh->primitives[p].indices != NULL) { - cgltf_accessor *attribute = data->meshes[i].primitives[p].indices; + cgltf_accessor *attribute = mesh->primitives[p].indices; model.meshes[meshIndex].triangleCount = (int)attribute->count/3; @@ -5341,7 +5407,7 @@ static Model LoadGLTF(const char *fileName) // raylib instead assigns to the mesh the by its index, as loaded in model.materials array // To get the index, we check if material pointers match, and we assign the corresponding index, // skipping index 0, the default material - if (&data->materials[m] == data->meshes[i].primitives[p].material) + if (&data->materials[m] == mesh->primitives[p].material) { model.meshMaterial[meshIndex] = m + 1; break; @@ -5391,6 +5457,8 @@ static Model LoadGLTF(const char *fileName) TRACELOG(LOG_ERROR, "MODEL: [%s] can only load one skin (armature) per model, but gltf skins_count == %i", fileName, data->skins_count); } + // XXX this is currently broken, due to the changes above + for (unsigned int i = 0, meshIndex = 0; i < data->meshes_count; i++) { for (unsigned int p = 0; p < data->meshes[i].primitives_count; p++)