Materials

A material bundles the surface parameters passed to a shader - colors, texture references, and PBR scalars. In the ECS, materials live on the MaterialComponent attached to an entity.

MaterialComponent

auto* obj = add_entity<Object>("Cube", glm::vec3(0, 0, -5));
obj->add_component<MaterialComponent>();

By default, MaterialComponent initializes with a plain white albedo and fully non-metallic, rough surface.

PBR Properties

Property	Type	Default	Description
albedo	glm::vec4	{1, 1, 1, 1}	Base color (RGBA)
metallic	float	0.0	Metallic factor [0, 1]
roughness	float	1.0	Roughness factor [0, 1]
ao	float	1.0	Ambient occlusion scalar
emissive	glm::vec3	{0, 0, 0}	Emissive color
emissive_strength	float	0.0	Emissive intensity multiplier

Texture Maps

Texture maps are set by referencing a registered Texture2D id:

auto* mat = obj->add_component<MaterialComponent>();
mat->set_albedo_map("albedo");
mat->set_normal_map("normal");
mat->set_metallic_roughness_map("metallic_roughness");
mat->set_ao_map("ao");
mat->set_emissive_map("emissive");

When a map is set, it takes precedence over the corresponding scalar property in the shader.

MaterialDescriptor

For batch registration, use MaterialDescriptor:

auto desc = MaterialDescriptor::create("rock");
desc->albedo       = glm::vec4(0.6f, 0.5f, 0.4f, 1.0f);
desc->roughness    = 0.9f;
desc->metallic     = 0.0f;
desc->albedo_map   = "rock_albedo";
desc->normal_map   = "rock_normal";

ResourceManager::get()->register_material(std::move(desc));

Then upload:

res->load_from_descriptors<MaterialDescriptor>(RendererBackend::OpenGL);

Attaching a Registered Material

obj->get_component<MaterialComponent>()->attach_material("rock");

This copies the descriptor's property values into the component and resolves the texture handles.

Rendering

GeometryPass iterates entities with MeshComponent, ResourceComponent, and MaterialComponent. It binds the resolved shader and uploads material properties as uniforms before issuing the draw call: