texture.hasAlpha causes clipping with PBR

Questions
1

I have noticed when a group of meshes with textures & faces fairly close, that setting hasAlpha = true causes clipping for a PBR material, while not for a STD material. Here is a side by side:

mh_combined
mh_combined.jpg1215×1296 107 KB

Which vertex “wins” varies, based on camera angle. Here is the head when scalp is winning:
head_pbr

I verified the problem by setting hasAlpha = false manually. Things are no longer spastic, but notice the eye browse & lower edge of the hair are not right.

eye_brows_pbr

The glTF exporter must be setting everything to false, because nothing shows through, but still also has problems where textures actually have alpha not pegged to 1.

Any recommendations?

2

pinging @sebavan

3

Yup you could like the gltf exporter set the transparency mode explicitely:

pbr.transparencyMode = PBRBaseMaterial.“one of those”:

/**
     * PBRMaterialTransparencyMode: No transparency mode, Alpha channel is not use.
     */
    public static readonly PBRMATERIAL_OPAQUE = 0;

    /**
     * PBRMaterialTransparencyMode: Alpha Test mode, pixel are discarded below a certain threshold defined by the alpha cutoff value.
     */
    public static readonly PBRMATERIAL_ALPHATEST = 1;

    /**
     * PBRMaterialTransparencyMode: Pixels are blended (according to the alpha mode) with the already drawn pixels in the current frame buffer.
     */
    public static readonly PBRMATERIAL_ALPHABLEND = 2;

    /**
     * PBRMaterialTransparencyMode: Pixels are blended (according to the alpha mode) with the already drawn pixels in the current frame buffer.
     * They are also discarded below the alpha cutoff threshold to improve performances.
     */
    public static readonly PBRMATERIAL_ALPHATESTANDBLEND = 3;
1 Like
4

PBRMATERIAL_ALPHATEST did it, thanks.

1 Like