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Artifacts in filter using texture as uniform

See original GitHub issue

I’m running into an issue with a simple custom filter that maps the colors in a grayscale image to a 256x1 gradient texture. There are strange artifacts throughout the filtered result. Could it be an issue with sampling pixels in the fragment shader?

Behavior

Steps to Reproduce

https://codepen.io/bryan_d/pen/JjbXrQJ

Environment

pixi.js 5.3.7
Browser: Chrome 88
OS: Windows 10

Issue Analytics

State:
Created 3 years ago
Comments:10 (4 by maintainers)

Top GitHub Comments

2reactions

ivanpopelyshevcommented, Mar 5, 2021

By default in v5 and v6 texture is mipmapped if its dimensions are powers of two.

For any color maps you have to use something like new PIXI.BaseTexture(document.querySelector(selector), { mipmap: 0, scaleMode: 0 });

color.r is not actually a good coord. (coord.r * 255.0 + 0.5) / 256.0 is the center of pixel in gradient texture, either use it in formulae either use scaleMode 0 (NEAREST)

mipmap 0 means POW2 , scaleMode 0 means NEAREST in pixi constants.

0reactions

bryan-dcommented, Mar 5, 2021

Confirmed, thanks for taking a look (and for the additional tip).