Shaders system

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Shader Pipeline Order

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Brakeza3D runs two independent shader chains per frame. Understanding their execution order is essential when you need to combine object-level and scene-level effects.

Frame loop steps (relevant to shaders)

Step	Name	Shaders that run
2	OnUpdateComponents	Object shaders — Mesh3D::customShaders for each mesh
3	LightPass	Built-in deferred ADS lighting (not user-scriptable)
6	PostProcessingShadersChain	Scene shaders — PostProcessingManager ping-pong FBOs

Object shaders (Mesh3D)

Object shaders are attached to individual Mesh3D (or Mesh3DAnimation) instances. They run during step 2 using the mesh's own geometry and texture-space UVs. They are configured in the editor under Object Properties → Custom Shaders.

• UVs are in texture space (0.0–1.0 across the mesh surface)
• Access the chain texture in code shaders via the SCENE data type
• Access the chain texture in node shaders via the Internal Texture (Color) node
• Do not sample the ping-pong chain texture as a mesh diffuse slot — UV spaces are incompatible

Scene shaders (PostProcessingManager)

Scene shaders operate on the entire rendered frame via a fullscreen quad ping-pong between two FBOs (both GL_RGBA16F color + GL_DEPTH_COMPONENT24 depth). They run during step 6, after lighting has been applied.

• UVs are in screen space: gl_FragCoord.xy / textureSize(sceneTexture, 0)
• Retrieve at runtime: Components:Render():getSceneShaderByLabel("label")
• Remove all at runtime: Components:Render():clearSceneShaders()

setSceneHidden and shader enable state

SceneLoader::setSceneHidden(name, false) (Lua: sceneLoader:setSceneHidden(name, false)) restores each scene shader to the enabled/disabled state it had when it was hidden. It does not unconditionally enable every shader — shaders that were already disabled before hiding remain disabled after un-hiding.

-- Hide a scene (suspends its objects and saves shader states)
sceneLoader:setSceneHidden("Interior", true)

-- Restore — shaders come back in exactly the state they left
sceneLoader:setSceneHidden("Interior", false)

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Shader Variables (uniforms)

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You can also configure the variables (uniforms) that each shader will receive from the UI.

You can create your own variables primitives vars:

• int
• float
• vec2
• vec3
• vec4
• texture

Or you can select system uniforms:

• delta_time (float)
• execution_time (float)
• scene (texture).

Additionally, geometry shaders (which only apply to Mesh3D) allow you to use system types such as diffuse or specular, with textures belonging to the particular model.

Postprocessing Shader Template

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Below are empty templates for the postprocessing shader.

VertexShader:

#version 330 core

layout (location = 0) in vec4 vertex; // <vec2 position, vec2 texCoords>

out vec2 TexCoords;

uniform mat4 model;
uniform mat4 projection;

void main()
{
    TexCoords = vec2(vertex.z, -vertex.w);
    gl_Position = projection * model * vec4(vertex.xy, 0.0, 1.0);
}

FragmentShader:

#version 330 core

in vec2 TexCoords;

//out vec4 FragColor;

void main()
{
   //FragColor = texture(sceneTexture, TexCoords);
}

Geometry Shader Template

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Below are empty templates for the geometry shader.

VertexShader:

#version 330 core

layout (location = 0) in vec3 aPos;
layout (location = 1) in vec3 aNormal;
layout (location = 2) in vec2 aTexCoords;

out vec3 FragPos;
out vec3 Normal;
out vec2 TexCoords;

uniform mat4 model;
uniform mat4 view;
uniform mat4 projection;

void main()
{
    FragPos = vec3(model * vec4(aPos, 1.0));
    Normal = mat3(transpose(inverse(model))) * aNormal;
    TexCoords = aTexCoords;

    gl_Position = projection * view * vec4(FragPos, 1.0);
}

FragmentShader:

#version 330 core

//uniform sampler2D diffuse;

out vec4 FragColor;

in vec3 FragPos;
in vec3 Normal;
in vec2 TexCoords;

void main()
{
    vec3 norm = normalize(Normal);
    vec3 viewDir = normalize(viewPos - FragPos);

    //FragColor = texture(diffuse, TexCoords);
}

Internal Shaders

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You can find the shaders that Brakeza3D uses internally in the /GLSL folder.

Mesh/Object Shaders

Shader	Files	Description
Render	Render.vs / Render.fs	Mesh3D forward rendering
Outliner	Outliner.vs / Outliner.fs	Outliner for a selected object
Color	Color.vs / Color.fs	Renders a Mesh3D with a given color
Wireframe	Wireframe.vs / Wireframe.fs	Renders vertices of a Mesh3D
Points	Points.vs / Points.fs	Renders vertices of a Mesh3D
Line3D	Line3D.vs / Line3D.fs	Renders 3D lines
Line	Line.vs / Line.fs	Draws a 2D line on screen
Image	Image.vs / Image.fs	Renders an image on screen
Particle	Particle.vs / Particle.fs	Draws a particle on screen; used by ParticleEmitter
Shading	Shading.vs / Shading.fs	Renders an object to a buffer to be used as a mask

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Postprocessing / Scene Shaders

Shader	Files	Description
FOG	FOG.vs / Fog.fs	Atmospheric fog effect
DepthMap	DepthMap.vs / DepthMap.fs	Draws the depth map of the scene
Tint	Tint.vs / Tint.fs	Colors the screen with a given color and alpha
BonesTransforms	BonesTransforms.vs	Bone transform calculations for skeletal animation
GBuffer	GBuffer.vs / GBuffer.fs	G-buffer pass for deferred rendering
LightingPass	LightingPass.vs / LightingPass.fs	Handles lighting computations for deferred pipeline
ShadowPass	ShadowPass.vs / ShadowPass.fs	Shadow mapping pass
ShadowPassDebugLight	ShadowPassDebugLight.vs / ShadowPassDebugLight.fs	Shadow debugging visualization
Grid	Grid.vs / Grid.fs	Debug grid overlay on the ground plane
GroundCircle	GroundCircle.vs / GroundCircle.fs	Selection circle projected on the ground, masked by G-Buffer geometry
GroundDecal	GroundDecal.vs / GroundDecal.fs	Decal texture projected onto the ground under an object
AxisQuad	AxisQuad.vs / AxisQuad.fs	Flat quad aligned to a world axis (used for markers/overlays)
Rect	Rect.fs	Filled rectangle for 2D UI drawing

If you know what you’re doing, you can freely manipulate the shaders as you see fit!

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Scripting API for Shaders

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You can retrieve and modify scene shaders at runtime from Lua using ComponentRender.

local shader = Components:Render():getSceneShaderByLabel("MyShader")
shader:setEnabled(true)
shader:setDataTypeValue("myUniform", value)

ShaderBaseCustomOGLCode methods

Method	Description
setEnabled(bool)	Enables or disables the shader in the pipeline
isEnabled()	Returns whether the shader is currently active
setDataTypeValue(name, value)	Sets a uniform value by name (float, int, vec2, vec3, vec4)
setTextureValue(name, texture)	Assigns a texture to the named sampler uniform