Camera to display only solid colour representations of entities?

Grimmy · May 16, 2023, 3:44pm

Is it possible to have an object that displays one material with one camera but a different material (or just a solid colour) in another camera?

Specifically I want my ‘regular’ camera (that the player sees through) to display regular materials/textures but a camera that is rendering to a texture at the same time to only see solid colours (no lighting etc).

Possible?

mvaligursky · May 16, 2023, 4:31pm

Yep. See PlayCanvas Examples - the debug rendering mode in the HUD. You can also override this chunk and output what you want for your camera, if you’re not happy with the debug options: engine/debug-output.js at main · playcanvas/engine · GitHub

here’s the documentation:

github.com

playcanvas/engine/blob/53ce553a4af00c87f4133fa18f21e31d6aa1242d/src/framework/components/camera/component.js#L118-L157


      
          /**
           * Sets the name of the shader pass the camera will use when rendering.
           *
           * @param {string} name - The name of the shader pass. Defaults to undefined, which is
           * equivalent to {@link SHADERPASS_FORWARD}. Can be:
           *
           * - {@link SHADERPASS_FORWARD}
           * - {@link SHADERPASS_ALBEDO}
           * - {@link SHADERPASS_OPACITY}
           * - {@link SHADERPASS_WORLDNORMAL}
           * - {@link SHADERPASS_SPECULARITY}
           * - {@link SHADERPASS_GLOSS}
           * - {@link SHADERPASS_METALNESS}
           * - {@link SHADERPASS_AO}
           * - {@link SHADERPASS_EMISSION}
           * - {@link SHADERPASS_LIGHTING}
           * - {@link SHADERPASS_UV0}
           *
           * Additionally, a new name can be specified, which creates a new shader pass with the given
           * name. The name provided can only use alphanumeric characters and underscores. When a shader

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Grimmy · May 17, 2023, 1:41am

Thanks, this is interesting but how exactly do I define the new CUSTOM_RENDERING_PASS. In a script somewhere? The chess demo doesnt seem to have any reference to how things get rendered nor does the camera component script link as far as I can tell.
Sorry, but I am very new when it comes to anything to do with shaders. Any clue how I could just render as a solid colour for each object for a different camera?

Cheers

mvaligursky · May 17, 2023, 7:57am

The hints are in my post above.

set up a shader pass for the camera you render to texture with. For example

cameraEntity.camera.setShaderPass('custom_rendering');

override debugOutputPS chunk on your materials, to tell it what you need for this pass

material.chunks.debugOutputPS  = `
#ifdef CUSTOM_RENDERING_PASS
gl_FragColor = vec4(1.0, 0.0, 0.0, 1.0);
#endif
`;

Grimmy · May 17, 2023, 8:04am

Thanks. How exactly do I do that bit? In which script?!? Do I make a new script?

Leonidas · May 17, 2023, 8:08am

Check some of the demo projects here, especially the ones using shader chunks on how to do that:

https://developer.playcanvas.com/en/tutorials/?tags=shaders