[SOLVED] Cannot sample Auxiliary buffer in Post Material, even though the Auxiliary debug output is correct.

[Guilherme.Nemeth]

I'm trying to render outline for interactive objects and was following both the docs (https://developer.unigine.com/ch/docs/future/content/materials/scriptable)  and this other topic (https://developer.unigine.com/forum/topic/7111-simple-outlinehighlight-effect/) which is very similar to what I want to do.

This hammer is the object I'm trying to render the outline of:

 

And this is the Shader Graph being used for the hammer:

 

Everything was going fine and I was able to render the desired object into the Auxiliary Buffer, but when I try to sample it in my custom Post Material I get nothing.

This is currently the Material I'm using, it's just a simple sampling of the Aux Buffer:

 

// More information on ULON format - https://developer.unigine.com/docs/code/formats/ulon_format
// More information on scriptable materials - https://developer.unigine.com/docs/content/materials/scriptable
BaseMaterial post_sobel <options_hidden=1 preview_hidden=1 var_prefix=var texture_prefix=tex>
{
	// Texture to be used in a shader (see Fragment shader below). Will be displayed in the Editor UI.
	Texture2D screen_texture <type=procedural internal=true>
	Texture2D auxiliary <type=auxiliary internal=true>

	// Custom parameter to be used in a shader (see Fragment shader below). Will be displayed in the Editor UI.
	Color selection_color = [0.5 0.5 0.5 1.0]
	Slider threshold = 1.0 <min=0.0 max=1.0>
	Slider distance = 1.0 <min=0.0 max=5.0>

	// Declaration of a custom rendering pass named 'selection_pass'. You can add as many passes as necessary.
	Pass selection_pass
	{
		// Shader declaration (you can add multiple shaders for a single pass)
		Fragment =
		#{
			#include <core/materials/shaders/render/common.h>

			STRUCT_FRAG_BEGIN
				INIT_COLOR(float4)
			STRUCT_FRAG_END

			MAIN_FRAG_BEGIN(FRAGMENT_IN)

				// take 3x3 samples
				float4 aux_color = TEXTURE_BIAS_ZERO(tex_auxiliary, IN_UV);

				// Choose between scene and selection colors
				OUT_COLOR = aux_color;

			MAIN_FRAG_END
		#}
	}

	// Expression written in Unigine Script to be called after the specified stage of the rendering sequence
	// the name should be the same as the corresponding callback of the Render class
	// (here RENDER_CALLBACK_END_POST_MATERIALS to execute it after rendering Post Materials)
	Expression RENDER_CALLBACK_END_POST_MATERIALS =
	#{
		// Get the screen color texture rendered for the current frame
		Texture screen_texture = engine.render_state.getScreenColorTexture();

		Texture source = engine.render.getTemporaryTexture(screen_texture);
		source.copy(screen_texture);

		// Set the source texture to be used as the 'screen_texture' in the shader
		setTexture("screen_texture", source);

		// Render the pass named 'selection_pass' and put the result to the screen color texture of the current frame
		renderPassToTexture("selection_pass", screen_texture);

		// Release the temporary texture
		engine.render.releaseTemporaryTexture(source);
	#}
}

 

This gives me a completely black screen, while the debug output of the Aux Buffer clearly shows the object:

 

 

The in-game debug view of the textures also show the object in the Aux Buffer:

 

Is there anything I'm doing wrong? Would appreciate any help, thanks!

 

 

 

 

[vovan675]

Hello. You need to use "source" instead of "type" in your Texture2D definitions

[Guilherme.Nemeth]

Wow, don't know how I missed that... That was it! Thank you very much.