Normal Map Download Format?

Hello I have a question about the normal map format when downloading Sketchfab models.

If I understand correctly, the Sketchfab online viewer uses the DirectX format, and thus normal maps uploaded in OpenGL format should be converted by checking the flip green button.

Is the flip green button only a display function of the Sketchfab online viewer, or is the uploaded normal map texture converted?
For example, when a user uploads an OpenGL normal map and checks the flip y button. When we then download his 3D model, do we get the original normal map texture in OpenGL or a converted DirectX normal map?

thank you for your time

I am not sure about other downloadable formats, but as far as I know with .blend files, any modifications made on sketchfab will not reflect in the downloaded blend file, including any supplementary image files
I could be wrong though

1 Like

Hi there,

When you download the source files, you will always get the original file formats.

For the glTF and USDZ versions of models, however, we will convert them as needed by the format.

2 Likes

Hello James, thank you for the explanation I marked it as the solution.

  1. So when downloading models online via the website for use in Blender:
    Since Blender uses the OpenGL normal map format, it makes sense to chose the glTF file option, which also uses OpenGL, so that possible DirectX normal maps are automatically converted?

  2. Regarding the Blender Sketchfab addon:
    Since the Blender Sketchfab addon is “Based on Blender glTF 2.0 Importer and Exporter from Khronos Group” then I assume it always uses the autoconverted glTF format?

  3. Original textures format vs glTF:
    In the help, it says: “textures are compressed to minimize model download times”. Does the glTF format conversion compress the textures a second time? Thus can there be a texture quality advantage when downloading the original uploaded file format, or will the quality of the textures be the same in the glTF converted version?

thank you for your help!