This page has been translated automatically.
Video Tutorials
Interface
Essentials
Advanced
How To
UnigineEditor
Interface Overview
Assets Workflow
Settings and Preferences
Working With Projects
Adjusting Node Parameters
Setting Up Materials
Setting Up Properties
Lighting
Landscape Tool
Sandworm
Using Editor Tools for Specific Tasks
Extending Editor Functionality
Built-in Node Types
Nodes
Objects
Effects
Decals
Light Sources
Geodetics
World Nodes
Sound Objects
Pathfinding Objects
Players
Programming
Fundamentals
Setting Up Development Environment
Usage Examples
C++
C#
UnigineScript
UUSL (Unified UNIGINE Shader Language)
Plugins
Rebuilding the Engine Tools
GUI
Double Precision Coordinates
API
Containers
Common Functionality
Controls-Related Classes
Engine-Related Classes
Filesystem Functionality
GUI-Related Classes
Math Functionality
Node-Related Classes
Objects-Related Classes
Networking Functionality
Pathfinding-Related Classes
Physics-Related Classes
Plugins-Related Classes
IG Plugin
CIGIConnector Plugin
Rendering-Related Classes
Content Creation
Content Optimization
Materials
Material Nodes Library
Miscellaneous
Input
Math
Matrix
Textures
Art Samples
Tutorials
Warning! This version of documentation is OUTDATED, as it describes an older SDK version! Please switch to the documentation for the latest SDK version.
Warning! This version of documentation describes an old SDK version which is no longer supported! Please upgrade to the latest SDK version.

Conditions

For each ULON node a logical condition can be specified using a state value. If the condition fails the node with all its children is ignored. Thus you can dynamically build the flexible hierarchy of ULON nodes. This can be useful when the contents of the node depends on certain parameters, e.g. a shader to be used is defined by the rendering pass.

Conditions are specified after the node's name, starting with the if keyword, the condition itself is enclosed in brackets [ ... ].

The syntax is the following:

ULON
Node name if [condition]

The Group nodes support the nested conditions:

ULON
Group parent if [condition]
{
	Group child if [condition]
}

Condition of the parent node is added to the condition of the child like so: (parent_conditon) && (child_conditon).

You can write complex conditions using logical operations:

ULON
Node name if [(state1 == 1 || state2 == 1) && !state3]

Preprocessor Auto Generation for Shaders#

In the UUSL code all conditions are enclosed in #if and #endif preprocessor on shader compilation, for instance:

ULON
StateInt do_a_thing = 1

Slider do_a_thing = 0.5 if [do_a_thing == 2]
Texture do_a_thing = black if [do_a_thing == 3]

Shader example =
#{ 
   // the following UUSL preprocessors are inlined on shader compilations
   #if DO_A_THING == 2
          UNIFORM float var_do_a_thing;
   #endif

   #if DO_A_THING == 3
          INIT_TEXTURE(0, tex_do_a_thing);
   #endif

   // the variable or the texture is available only when the corresponding condition is met 
   color.r = var_do_a_thing; // valid only when do_a_thing = 2
   color.gb = TEXTURE(tex_do_a_thing, IN_UV); // valid only when do_a_thing = 3
#}

Usage Examples#

ULON
Int some_var = 1 <min=0 max=1>
		
Pass deferred if [some_var == 0]
{
	Vertex = "shaders/a.vert"
	Fragment = "shaders/a.frag"
}

Pass deferred if [some_var == 1]
{
	Vertex = "shaders/b.vert"
	Fragment = "shaders/b.frag"
}

Based on the value of some variable you can specify different shaders for the same render pass (deferred in our example).

Last update: 2021-12-13
Build: ()