gltf_io.h File Reference

Write scenes to glTF 2.0 (.gltf + .bin) or binary glTF (.glb). More...

#include <scimesh/scene.h>
#include <scimesh/camera.h>
#include <scimesh/mesh.h>
#include <scimesh/normals.h>
#include <string>
#include <vector>
#include <cstdint>
#include <cctype>
#include <algorithm>
#include <fstream>
#include <sstream>
#include <iomanip>
#include <stdexcept>

Include dependency graph for gltf_io.h:

Go to the source code of this file.

Classes
struct	scimesh::gltf_io::detail::PackedMesh
	One mesh, packed into glTF-ready flat arrays. More...
struct	scimesh::gltf_io::detail::GltfOutput
	Serialized glTF scene: the JSON document plus the binary buffer. More...

Namespaces
namespace	scimesh
namespace	scimesh::gltf_io
namespace	scimesh::gltf_io::detail

Functions
std::string	scimesh::gltf_io::detail::json_escape (const std::string &s)
std::string	scimesh::gltf_io::detail::fmt (float v)
	Print a float compactly with enough digits to round-trip a float32.
std::string	scimesh::gltf_io::detail::join_impl (const std::vector< std::string > &v)
void	scimesh::gltf_io::detail::append_vertex (PackedMesh &pm, const Vec3 &v, const std::vector< Vec3 > *normals, uint32_t idx, const Color *color)
PackedMesh	scimesh::gltf_io::detail::pack_mesh (const Mesh &mesh)
void	scimesh::gltf_io::detail::pad_bin (std::vector< uint8_t > &bin, size_t align=4)
GltfOutput	scimesh::gltf_io::detail::build (const Scene &scene, const Camera *camera)
std::string	scimesh::gltf_io::detail::basename (const std::string &path)
std::string	scimesh::gltf_io::detail::dirname (const std::string &path)
std::string	scimesh::gltf_io::detail::stem (const std::string &path)
void	scimesh::gltf_io::detail::write_bytes (const std::string &path, const std::vector< uint8_t > &data)
void	scimesh::gltf_io::write_gltf (const std::string &path, const Scene &scene, const Camera *camera=nullptr)
	Write a scene as glTF 2.0 (JSON document + external .bin file).
void	scimesh::gltf_io::write_glb (const std::string &path, const Scene &scene, const Camera *camera=nullptr)
	Write a scene as a single binary glTF file (.glb).
void	scimesh::gltf_io::write (const std::string &path, const Scene &scene, const Camera *camera=nullptr)
	Write a scene as glTF, choosing the format from the file extension.

Detailed Description

Write scenes to glTF 2.0 (.gltf + .bin) or binary glTF (.glb).

This is a one-way export: after a scene is written to a glTF file, the browser/GPU side is out of scimesh's scope. The library stays a CPU mesh renderer and simply emits a standard, shareable scene file.

What is exported

• Geometry: vertex positions (FLOAT32), normals (FLOAT32) when present (computed if missing, matching what the renderer does), indices (UINT32).
• Vertex colors mapped to the glTF COLOR_0 attribute (normalized UNSIGNED BYTE RGBA). Per-face colors have no direct glTF equivalent, so they are exported by splitting vertices (each triangle gets its own three vertices), increasing geometry ~3x.
• Per-mesh placement transforms as node matrix (column-major, matching what the renderer applies) and node names.
• An optional perspective camera (when a Camera* is supplied).
• Diffuse materials (metallicFactor 0, roughnessFactor 1): scimesh is not physically-based, so exports default to fully diffuse so they are not rendered pitch black by PBR viewers.

Renderer-specific settings (shading mode, fog, SSAO, ...) are deliberately NOT exported — they are not part of the glTF standard.

Usage

Scene scene;
scene.add(sphere);
scene.add("cube", cube, glm::translate(Mat4(1.0f), Vec3(2, 0, 0)));
gltf_io::write_gltf("out/model.gltf", scene);   // .gltf + .bin
gltf_io::write_glb("out/model.glb", scene);     // single binary file

See also

Scene, Scene::add(), write_stl()

Definition in file gltf_io.h.