Scriptable Materials

• UnigineScript API sample <UnigineSDK>/data/samples/shaders/scriptable_00

1. Create the post_sobel.basemat text file in the data/materials folder and open it in a plain text editor.
2. Specify the name for the base material and attributes for it.
   Source Code (ULON)

   BaseMaterial post_sobel <preview_hidden=1 var_prefix=var texture_prefix=tex>
   {
   ...
   }

3. Describe material's resources and parameters.
   Source Code (ULON)

   // specify an internal texture to be used
   Texture src_color <source=procedural internal=true>
   
   // define the material's states and parameters available in the Editor
   Group "Sobel operator"
   {
   	State multiply = false
   	Slider threshold = 1.0 <min=0.0 max=1.0>
   	Slider scale = 1.0 <min=0.0 max=1.0>
   }

4. Write the fragment shader for the custom outline render pass.
   Source code (UUSL)

   // define the outline render pass
   Pass render_sobel_operator
   {
   	// write the fragment shader in UUSL or HLSL/GLSL
   	Fragment=
   	#{
   		#include <core/materials/shaders/render/common.h>
   		
   			STRUCT_FRAG_BEGIN
   				INIT_COLOR(float4)
   			STRUCT_FRAG_END
   			
   			MAIN_FRAG_BEGIN(FRAGMENT_IN)
   			// get the inverse resolution of the viewport (1.0 / width, 1.0 / height)
   			float2 offset = s_viewport.zw; 
   			
   			// take 3x3 samples
   			OUT_COLOR = TEXTURE_BIAS_ZERO(tex_src_color, IN_UV);
   			
   			float3 c0 = TEXTURE_BIAS_ZERO(tex_src_color, IN_UV + offset * float2( 1, 0)).rgb;
   			float3 c1 = TEXTURE_BIAS_ZERO(tex_src_color, IN_UV + offset * float2( 0, 1)).rgb;
   			float3 c2 = TEXTURE_BIAS_ZERO(tex_src_color, IN_UV + offset * float2( 1, 1)).rgb;
   			float3 c3 = TEXTURE_BIAS_ZERO(tex_src_color, IN_UV + offset * float2( 1, -1)).rgb;
   			
   			float3 c4 = TEXTURE_BIAS_ZERO(tex_src_color, IN_UV + offset * float2(-1, 0)).rgb;
   			float3 c5 = TEXTURE_BIAS_ZERO(tex_src_color, IN_UV + offset * float2( 0, -1)).rgb;
   			float3 c6 = TEXTURE_BIAS_ZERO(tex_src_color, IN_UV + offset * float2(-1, -1)).rgb;
   			float3 c7 = TEXTURE_BIAS_ZERO(tex_src_color, IN_UV + offset * float2(-1, 1)).rgb;
   			
   			// find edge with Sobel filter
   			float3 sobel_x = c6 + c4 * 2.0f + c7 - c3 - c0 * 2.0f - c2;
   			float3 sobel_y = c6 + c5 * 2.0f + c3 - c7 - c1 * 2.0f - c2;
   			float3 sobel = sqrt(sobel_x * sobel_x + sobel_y * sobel_y);
   			
   			// apply threshold
   			float edge = saturate(1.0f - dot(sobel, toFloat3(var_threshold)));
   			
   			// apply scale
   			float3 result = saturate(OUT_COLOR.rgb + var_scale) * edge;
   			
   			#ifdef STATE_MULTIPLY
   				OUT_COLOR.rgb *= result; // for colored result
   			#else
   				OUT_COLOR.rgb = result; // for black & white result
   			#endif
   		MAIN_FRAG_END
   	#}
   }

5. Write the Expression callback in Unigine Script to be called after the Post Materials stage (RENDER_CALLBACK_END_POST_MATERIALS) of the render sequence to perform outline render pass with Sobel filter.
   Source code (UnigineScript)

   // the expression in Unigine Script defines a callback 
   Expression RENDER_CALLBACK_END_POST_MATERIALS = 
   #{
   	// declare the source texture from the screen frame
   	Texture source = engine.render.getTemporaryTexture(engine.render_state.getScreenColorTexture());
   	// define the source texture from the screen frame
   	source.copy(engine.render_state.getScreenColorTexture());
   	//set the color source texture to use it in the shader
   	setTexture("src_color", source);
   	// render the outline result texture to output it to the screen 
   	renderPassToTexture("render_sobel_operator", engine.render_state.getScreenColorTexture());
   	// release the temporaty texture
   	engine.render.releaseTemporaryTexture(source);
   #}

6. The full source code for the material is given below. You can copy it to the post_sobel.basemat and save the file.
   Source code

   BaseMaterial post_sobel <preview_hidden=1 var_prefix=var texture_prefix=tex>
   {
   // specify an internal texture to be used
   Texture src_color <source=procedural internal=true>
   
   // define the material's states and parameters available in the Editor
   Group "Sobel operator"
   {
   	State multiply = false
   	Slider threshold = 1.0 <min=0.0 max=1.0>
   	Slider scale = 1.0 <min=0.0 max=1.0>
   }
   
   // define the outline render pass
   Pass render_sobel_operator
   {
   	// write the fragment shader in UUSL or HLSL/GLSL
   	Fragment=
   	#{
   		#include <core/materials/shaders/render/common.h>
   		
   			STRUCT_FRAG_BEGIN
   				INIT_COLOR(float4)
   			STRUCT_FRAG_END
   			
   			MAIN_FRAG_BEGIN(FRAGMENT_IN)
   			// get the inverse resolution of the viewport (1.0 / width, 1.0 / height)
   			float2 offset = s_viewport.zw; 
   			
   			// take 3x3 samples
   			OUT_COLOR = TEXTURE_BIAS_ZERO(tex_src_color, IN_UV);
   			
   			float3 c0 = TEXTURE_BIAS_ZERO(tex_src_color, IN_UV + offset * float2( 1, 0)).rgb;
   			float3 c1 = TEXTURE_BIAS_ZERO(tex_src_color, IN_UV + offset * float2( 0, 1)).rgb;
   			float3 c2 = TEXTURE_BIAS_ZERO(tex_src_color, IN_UV + offset * float2( 1, 1)).rgb;
   			float3 c3 = TEXTURE_BIAS_ZERO(tex_src_color, IN_UV + offset * float2( 1, -1)).rgb;
   			
   			float3 c4 = TEXTURE_BIAS_ZERO(tex_src_color, IN_UV + offset * float2(-1, 0)).rgb;
   			float3 c5 = TEXTURE_BIAS_ZERO(tex_src_color, IN_UV + offset * float2( 0, -1)).rgb;
   			float3 c6 = TEXTURE_BIAS_ZERO(tex_src_color, IN_UV + offset * float2(-1, -1)).rgb;
   			float3 c7 = TEXTURE_BIAS_ZERO(tex_src_color, IN_UV + offset * float2(-1, 1)).rgb;
   			
   			// find edge with Sobel filter
   			float3 sobel_x = c6 + c4 * 2.0f + c7 - c3 - c0 * 2.0f - c2;
   			float3 sobel_y = c6 + c5 * 2.0f + c3 - c7 - c1 * 2.0f - c2;
   			float3 sobel = sqrt(sobel_x * sobel_x + sobel_y * sobel_y);
   			
   			// apply threshold
   			float edge = saturate(1.0f - dot(sobel, toFloat3(var_threshold)));
   			
   			// apply scale
   			float3 result = saturate(OUT_COLOR.rgb + var_scale) * edge;
   			
   			#ifdef STATE_MULTIPLY
   				OUT_COLOR.rgb *= result; // for colored result
   			#else
   				OUT_COLOR.rgb = result; // for black & white result
   			#endif
   		MAIN_FRAG_END
   	#}
   }
   
   // the expression in Unigine Script defines a callback 
   Expression RENDER_CALLBACK_END_POST_MATERIALS = 
   #{
   	// declare the source texture from the screen frame
   	Texture source = engine.render.getTemporaryTexture(engine.render_state.getScreenColorTexture());
   	// define the source texture from the screen frame
   	source.copy(engine.render_state.getScreenColorTexture());
   	//set the color source texture to use it in the shader
   	setTexture("src_color", source);
   	// render the outline result texture to output it to the screen 
   	renderPassToTexture("render_sobel_operator", engine.render_state.getScreenColorTexture());
   	// release the temporaty texture
   	engine.render.releaseTemporaryTexture(source);
   #}
   }

1. Launch the UNIGINE Editor via the SDK Browser. In the Materials tab, you will find the imported post_sobel material in the list of base materials.
   
2. To apply the material globally, go to Windows -> Settings and in the Custom Post Materials section click Add New Material. Assign the post_sobel material by dragging it to the field or by specifying the name of the material.
3. Click create a child material to be able to specify states and parameters of the material. The new child material of the post_sobel will be created and assigned here.
   
4. Check Multiply to make a colorful final image. Adjust the Threshold and Scale values to customize the effect.
   The applied post process outline effect.

That's it! You have just created a scriptable material for all of the application’s cameras. To apply the post process effect only to a specific camera, go to the Parameters tab of the corresponding Player node and assign the material to it.