Document new post-import plugin preprocessing stage to amend settings

[fire]

Your Godot version:

godotengine/godot@6dc78c8

Issue description:

Update the documentation.

Allow post-import plugins to modify _subresources godotengine/godot#100792

The use case is to write the .import manually. For example, take a glTF2 character and add HumanoidProfile remapping via script.

This was added as a last-minute advanced post-import plugin feature: post-import plugins can amend the ["_subresources"]["nodes"]["PATH:Armature/Skeleton3D"]["retarget/bone_map"] settings from the preprocessing phase of a post import plugin

We can do it by writing a custom .import file, or we can do it with a plugin.

URL to the documentation page (if already existing):

https://docs.godotengine.org/en/stable/tutorials/plugins/editor/import_plugins.html

[fire]

See also godotengine/godot#95461

[GuilhermeGSousa]

The feature works great as a plugin, I agree updating the docs is needed. Here's what I've been using to edit animation import settings on pre import for posteriority:

void AnimationPostImportPlugin::_pre_process(Node* p_scene) {

    const String export_path = get_option_value("export/animation_export_path");

    if (export_path.is_empty()) {
        return;
    }

    Dictionary animations;
    _export_animations(p_scene, animations, export_path);

    Dictionary subresources = get_option_value("_subresources");
    subresources["animations"] = animations;
}

[fire]

See also https://github.com/GuilhermeGSousa/godot-motion-matching/pull/86/files

[SamDevelopsCode]

We can do it by writing a custom .import file, or we can do it with a plugin.

We don't need to use a plugin? This can be achieved with just a custom import script? By this, I specifically mean changing the subresources, like changing the bonemap

[fire]

A custom import script is too late. You'll need to recode the bone map algorithm in gdscript.. which we've done in godot-vrm.

Edited:

The preprocessing stage is to modify the input parameters to the importer.

Changing the bone map is straightforward. The algorithm to turn the existing bones to the Humanoid Profile is what is wanted without reimplementing it.