To create an ORM texture, an incorrect value is passed

[AndreyPrakhov]

Description of the bug

The gbuffer-metalness.frag chunk uses 'metalness'

#ifdef out_ORM

	out_ORM.z = metalness;

#endif

In the THREE shader chunk the code looks like this (metalnessmap_fragment.glsl.js):

float metalnessFactor = metalness;

#ifdef USE_METALNESSMAP

	vec4 texelMetalness = texture2D( metalnessMap, vMetalnessMapUv );

	// reads channel B, compatible with a combined OcclusionRoughnessMetallic (RGB) texture
	metalnessFactor *= texelMetalness.b;

#endif

In theory, the correct code to fill the buffer should look like this:

#ifdef out_ORM

	out_ORM.z = metalnessFactor;

#endif

Library versions used

• Three: [162]
• Post Processing: v7.0.0-alpha.3

[vanruesc]

Thanks for pointing this out! It will be fixed in the next release via cdd1558.

Until then you can use the following snippet to patch it right after instantiating the RenderPipeline:

const pipeline = new RenderPipeline(...);

ShaderChunk.metalnessmap_fragment = ShaderChunk.metalnessmap_fragment.replace(
    "out_ORM.z = metalness;",
    "out_ORM.z = metalnessFactor;"
);

[vanruesc]

Fixed in postprocessing@7.0.0-alpha.4.