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Rebel Fork Framework
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Technique defines exact sequence of steps used to render geometry to scene.
Technique consists of one or multiple passes which are used by the engine in different circumstances. Each pass may use unique configuration of shaders and render device settings.
Technique may also have global shader name and defines which will be used by default within this Technique. There's also desktop flag which can be used to disable whole Technique on mobile platforms. Make sure that Material has fallback Technique(s) to use in this case.
| Name | Description | Default Value |
|---|---|---|
| name | Name of the pass. Used to access pass from code and defines semantics for standard passes. | |
| [v,p]s | Shaders used for rendering. | |
| [v,p]sdefines | Shader defines used to compile shaders. | (empty) |
| [v,p]sexcludes | Shader defines excluded for this pass from the list of defines. Useful to suppress Material or Technique defines for specific passes. | (empty) |
| blend | Color blend mode used for rendering. See table below. | replace |
| cull | Overrides cull from Material description. | (inherited) |
| depthtest | Depth test used for rendering. See table below. | lessequal |
| depthwrite | Whether to write surface depth to the depth buffer. | true |
| alphatocoverage | If true, overrides alphatocoverage from Material. | false |
src - color of the surface rendered with this pass.src_alpha - alpha value returned from the shader of the surface.dest - color in the backbuffer.dest_alpha - alpha value in the backbuffer.output - final color stored in the backbuffer.| Name | Formula |
|---|---|
| replace | output = src |
| add | output = dest + src |
| multiply | output = dest * src |
| alpha | output = dest * (1 - src_alpha) + src * src_alpha |
| addalpha | output = dest + src * src_alpha |
| premulalpha | output = dest * (1 - src_alpha) + src |
| invdestalpha | output = dest * dest_alpha + src * (1 - dest_alpha) |
| subtract | output = dest - src |
| subtractalpha | output = dest - src * src_alpha |
src_depth - depth of the surface.dest_depth - depth stored in depth buffer.| Name | Condition |
|---|---|
| always | true |
| equal | src_depth == dest_depth |
| less | src_depth < dest_depth |
| lessequal | src_depth <= dest_depth |
| greater | src_depth > dest_depth |
| greaterequal | src_depth => dest_depth |
Standard passes are listed in sections below. Technique for default render pipeline usually needs either Opaque or Transparent passes, and some or all of utility passes.
For opaque geometries, at least base and light passes should be present.
| Name | Description |
|---|---|
| base | Used to render opaque geometry for the first time. URHO3D_AMBIENT_PASS shader define is present during this pass. |
| light | Used to apply lighting to already rendered opaque geometry. URHO3D_LIGHT_PASS shader define is present during this pass. |
| litbase | Used to render opaque geometry for the first time and apply lighting from one light source. Both URHO3D_AMBIENT_PASS and URHO3D_LIGHT_PASS passes are present during this pass. |
| deferred | Used to render opaque geometry if Deferred lighting is enabled. If this pass is missing, Forward lighting will be used as fallback. URHO3D_GBUFFER_PASS shader define is present during this pass. |
For transparent geometries, both alpha and litalpha passes should be present.
| Name | Description |
|---|---|
| alpha | Used to render transparent geometry for the first time. If blend is set to replace, backbuffer color will be provided as readable texture (if possible). It can be used to render refractive surfaces like water or hot air. URHO3D_AMBIENT_PASS shader define is present during this pass. If URHO3D_LIGHT_PASS shader define is present as well, shader is expected to apply lighting as well (like in litalpha). |
|**litalpha**|Used to apply lighting to already rendered transparent geometry. URHO3D_LIGHT_PASS shader define is present during this pass.||
Optional.
| Name | Description |
|---|---|
| shadow | Used to render shadow cast by the geometry. If absent, no shadow will be rendered. URHO3D_DEPTH_ONLY_PASS shader define is present during this pass. |
| depth | Used to render geometry to depth buffer during depth pre-pass. If absent, geometry is ignored during depth pre-pass. URHO3D_DEPTH_ONLY_PASS shader define is present during this pass. |
All non-standard user passes are ignored by default RenderPipeline. They can be used in arbitrary user code.
Materials that use lit techniques will receive lighting from direct, indirect and ambient light sources.
| Name | Description |
|---|---|
| LitOpaque | Opaque surface. Note that surfaces that use ALPHAMASK macro to make holes in the geometry are also considered opaque. |
| LitTransparent | Translucent surface with physically correct bright specular highlights (e.g. glass). |
| LitTransparentFade | Translucent surface with unrealistic faded specular highlights (e.g. hologram or ghost). |
| LitWater | Water technique: distorts and fades background objects. |
| LitLegacyTerrain | Legacy terrain shader that supports up to 3 diffuse textures blended by mask. |
There are aliases for techniques with NORMALMAP defined. The only difference is that normal map from Material is used when possible.
| Name | Description |
|---|---|
| LitOpaqueNormalMap | Same as LitOpaque but with normal mapping. |
| LitTransparentNormalMap | Same as LitTransparent but with normal mapping. |
| LitTransparentFadeNormalMap | Same as LitTransparentFade but with normal mapping. |
Unlit techniques ignore all scene lighting and render input textures "as is".
| Name | Description |
|---|---|
| UnlitOpaque | Opaque surface. Note that surfaces that use ALPHAMASK macro to make holes in the geometry are also considered opaque. |
| UnlitTransparent | Translucent surface. |