oe::scene::loader::Gltf Class Reference

Loader to load Khronos glTF assets. More...

#include <OxygenEngine/scene/loader/gltf.h>

Inheritance diagram for oe::scene::loader::Gltf:

Classes
struct	GltfSceneData
struct	GltfTextureList
	Load the glTF asset into a scene (a new root node will be created) More...

Public Types
using	MeshFlags = uint8_t

Public Member Functions
	Gltf (const std::string &filename)
	Load a glTF asset from a file.
GltfSceneData	convertSceneData (oe::scene::NodePtr root_node, uint16_t id_scene=0) const
	Convert the glTF asset into scene data under the specified node.
GltfTextureList	convertTextures (render::TextureManager &texture_manager, std::string_view prefix) const
	Load model textures.
void	setMaterialFiller (std::function< void(const GltfPbrMaterial &gltf_material, Material &oe_material)> material_filler)
	Apply application specific properties on the materials.
std::vector< Material >	convertMaterials (GltfTextureList textures) const
	Convert and return materials.
Material	generateDefaultMaterial () const
	Generate a default material suitable for glTF rendering.

Protected Member Functions
void	_custom_load (const std::string &filename)

Protected Attributes
std::function< void(const GltfPbrMaterial &, Material &)>	_material_filler = {}
	std::list<std::pair<oe::scene::Mesh, int32_t>> _primitives;
tinygltf::TinyGLTF *	_loader
tinygltf::Model *	_model
std::function< void(const std::string &extension, NodePtr root_node, const nlohmann::json &extension_data, const bool pre_load)>	_custom_asset_extension_handler = {}
std::function< void(const std::string &extension, NodePtr node, const nlohmann::json &extension_data)>	_custom_node_extension_handler = {}
std::function< void(const std::string &extension, Material &material, const nlohmann::json &extension_data)>	_custom_material_extension_handler = {}

Detailed Description

Loader to load Khronos glTF assets.

Example

// Prepare the loader
oe::scene::loader::Gltf gltf_model = {filename};
 
// Load assets textures with the specified texture_manager
gltf_model.convertTextures(my_texture_manager);
 
// (optional) Add any custom handlers if you want to customize how the asset is imported
// Here are some examples:
{
    // Set a custom material converter
    gltf_model.setMaterialFiller(my_gltf_material_filler);
 
    // Customize how the material is applied on nodes
    gltf_model.setNodeMaterialModifier(my_gltf_node_material_modifier);
}
 
// Finally, we can import the glTF asset hierarchy into the scene and retrieve its root node
oe::scene::Node& imported_node = gltf_model.addIntoSceneManager(my_scene_manager);

The loader will automatically handle the following glTF extensions:

• KHR_lights_punctual (only point lights)
• KHR_texture_transform (only offset and scale, taken from base color texture only)
• KHR_materials_ior
• KHR_materials_transmission
• KHR_materials_volume
• OE_materials_roughnessMetallicOcclusion

Note

If you want to handle additional / custom extensions, take a look at GltfWithExtensions

Constructor & Destructor Documentation

Gltf()

oe::scene::loader::Gltf::Gltf

(

const std::string &

filename

)

Load a glTF asset from a file.

Parameters

filename

path to the glTF asset

Member Function Documentation

convertMaterials()

std::vector< Material > oe::scene::loader::Gltf::convertMaterials

(

GltfTextureList

textures

)

const

Convert and return materials.

Note

if you need to add custom properties, you can use setCustomMaterialFiller()

Returns

Generated and converted materials

convertSceneData()

GltfSceneData oe::scene::loader::Gltf::convertSceneData	(	oe::scene::NodePtr	root_node,
		uint16_t	id_scene = 0
	)		const

Convert the glTF asset into scene data under the specified node.

Parameters

root_node	Asset's root nodes will be imported as children of this node
id_scene	glTF scene to load

Returns

Converted glTF scene

convertTextures()

GltfTextureList oe::scene::loader::Gltf::convertTextures	(	render::TextureManager &	texture_manager,
		std::string_view	prefix
	)		const

Load model textures.

prefix can be anything you want, but it must be unique for gltf asset (ie. if you load the same asset multiple times, the prefix should be the same)

Will generate textures named prefix_X and prefix_RMA_Y|Z in the Texture manager

• X is the texture id / position (in glTF data)
• Y, Z are occlusion and roughness textures ids / position (in glTF data) used to generate the RouMetAo texture

Parameters

texture_manager
prefix	Texture prefix in the texture manager

Returns

a list of loaded textures: keys are id and values are the name + pointer to the texture (owned by the Texture manager)

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The documentation for this class was generated from the following file:

• OxygenEngine/scene/loader/gltf.h