Before, models (of traditional lighting models) with specularity/glossiness would be completely flat when exported to metallicRoughness. These changes approximate glossiness (as an inverse of roughness, with specular intensity as a multiplier) both reading from gltf2 and writing to gltf2.
The changes here (which only apply to reading from or writing to pbrSpecularGlossiness) will:
- store and read specular color on `AI_MATKEY_COLOR_SPECULAR ` rather than `AI_MATKEY_GLTF_PBRSPECULARGLOSSINESS_SPECULAR_FACTOR`
- store and read specular texture from `aiTextureType_SPECULAR` rather than `AI_MATKEY_GLTF_PBRSPECULARGLOSSINESS_SPECULARGLOSSINESS_TEXTURE`. Even though pbrSG’s specularGlossiness texture uses the alpha channel for glossiness, it will still work well enough with just the RGB channels of the image
These changes do a better of importing and exporting baseColor colors and textures, as well as diffuse colors and textures (in the case of pbrSpecularGlossiness)
- baseColorFactor will be stored on both `$clr.diffuse` and `$mat.gltf.pbrMetallicRoughness.baseColorFactor`, and will be extracted from `$mat.gltf.pbrMetallicRoughness.baseColorFactor` first, and falling back to `$clr.diffuse`. The behaviour for baseColorTexture is similar
- pbrSG’s diffuseFactor will now only be store on `$clr.diffuse` (overwriting any previous assignments to `$clr.diffuse`, e.g. from metallicRoughness’ baseColorFactor, as diffuseFactor is more analogous to diffuse color than baseColor), and will only extract from `$clr.diffuse`
alphaMode is now converted from a std::string to an aiString and back to std::string, since aiString is easier to store and retrieve from aiMaterial properties than std::string
Fixes issues of alphaMode being written out as `\fOPAQUE\0\0\0\0\0\0…`
Previously, only one primitive was supported, in fact memory was corrupted
when more than one primitive was found per glTF mesh.
In this change, each primitive is unrolled as a new Assimp Mesh, resulting
in multiple Assimp meshes per node when multiple primitives exist per
glTF mesh. This is required in the general case, since glTF primitives can
have different material bindings and primitive modes.
Samplers are now imported into assimp internal format from textures;
Samplers have defaults as per spec;
Sampler enums are strongly typed with UNSET values;
Samplers are exported properly;
Sampler filters are exported as well;
Samplers are re-used across textures on export
Default sampler values are not written
pbrMetallicRoughness and pbrSpecularGlossiness as structs; persist textureinfo properties from start to finish; persist pbrSpecularGlossiness (via extensionsUsed) usage from start to finish
Daniel Hritzkiv
Kim Kulling
Jeremy Cowles
John Senneker