I asked Andres Colubri if he could help me out with getting stencils to work in processing. Here it is, and it’s freaking awesome. [12] // Adapted from https://learnopengl.com/Advanced-OpenGL/Stencil-testing void setup() { size(600, 600, P3D); noStroke(); } void draw() { PGL pgl = beginPG…

[image] clankill3r: stencils What’s this please? Can you elaborate?

[image] clankill3r: single_color.glsl Could you please share single_color.glsl ?

The shader was in the first post, but I changed it so a shader is not needed anymore. Stencils can be used to discard fragments (pixels). In the above example the outline is drawn after the box is drawn and not the other way around. I need to use stencils for clipping cause the opengl scissor does…

[image] clankill3r: I changed it so a shader is not needed anymore I don’t get it. Your code says sh = loadShader("single_color.glsl"); but you don’t provide a link to a glsl file, or the contents of that file. If you don’t need it, why are you loading it? If you do need it, can you share it? …

Thanks for sharing this! Cool visual effect. I have never used beginPGL / endPGL in a sketch before – it took me a while to figure out how the sketch builds the scene in three stages (the platform, the box, and the unlit scaled red box to appear “behind” it). Particularly interesting that the outli…

[image] OpenGL processing shader sheet Gallery I made a google docs about what variables are used in what shader. It might be usefull to someone some day. Chrisir

For my own understanding I created an annotated version of this that lets you scale the box and outline interactively using mouseX / mouseY. The outline is impressive – although the illusion breaks a bit if they both cross too far into the platform and you start seeing them double-intersecting. //…

Using stencils in P2D / P3D

Gallery

Chrisir August 17, 2019, 4:46pm 8

Chrisir

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Using stencils in P2D / P3D

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