Weird lighting artefacts using PP materials

Hi, I’m currently tryin’ to use some PP materials to get a decent cel-shading, but can’t figure out why I have these weird artefacts on barely every object.

May I ask if it’s convenient for you to display your ppm material? This may seem like some values are beyond the engine’s limit, but the specific problem still needs to be determined by how your material is calculated. Alternatively, you can check if there are any values that exceed 0-1, such as the alpha of lerp node.