Can't seem to add any component. about blender_bevy_toolkit

[sdfgeoff]

In order to add a component you need to tell the exporter what components are available in your game.

The editor looks for files in a 'component_defintions' folder in the same directory as your blend file. Eg:

You can see some examples for these files in the core_definitions and rapier_definitions folders, or look at the ones below:

Simple "tag" struct

{
    "name": "GncComputer",
    "description": "Coordinates RCS thrusters and main engines to produce a desired motion",
    "id": "space_ship_gnc_computer",
    "struct": "game::ship_parts::gnc_computer::GncComputer",
    "fields": []
}

Simple parameter:

{
    "name": "Engine",
    "description": "Used to apply thrust to an object",
    "id": "space_ship_engine",
    "struct": "game::ship_parts::engine::Engine",
    "fields": [
        {
            "field": "max_thrust_newtons", 
            "type": "f64", 
            "default": 10.0,
            "description": "The max amount of force the engine can apply, measured in Newtons"
        }
    ]
}

Actually, I remember this didn't work on windows a couple months back. One of my friends fixed it, let me push the changes.

[Joe23232]

@sdfgeoff

So in regards to this image, so if I had all of these files, then suddenly if I go to "add component" in Blender, then I will see all the components such as clock.json, com_node.json etc?

So how does the json files work, what would I put inside the json files? Or does it get auto generated?

Actually, I remember this didn't work on windows a couple months back. One of my friends fixed it, let me push the changes.

So when you push the changes, do I have to reinstall the Blender extension?

[sdfgeoff]

@Joe23232 I've just pushed the changes. Yes you will have to re-install the addon.

What you put inside the JSON files depends on what components you have in your game.

Eg from the example above:

{
    "name": "Engine",
    "description": "Used to apply thrust to an object",
    "id": "space_ship_engine",
    "struct": "game::ship_parts::engine::Engine",
    "fields": [
        {
            "field": "max_thrust_newtons", 
            "type": "f64", 
            "default": 10.0,
            "description": "The max amount of force the engine can apply, measured in Newtons"
        }
    ]
}

• "name" => What appears in blender
• "description" => Text that appears when you over over it in blender
• "id" => Should be unique for this component. (Used to store data internally to the blend file between saves)
• "struct" => This is a path to the struct that represents your object in bevy. Finding this can be a bit hard as it doesn't follow through pub use statements, it has to be the path to the module where the struct is actually defined.
• "fields" => These are what properties the component has. For example, in rust, the engine looks like:

/// An engine applies thrust to the spacecraft
use bevy::prelude::*;

#[derive(Reflect, Default)]
#[reflect(Component)]
pub struct Engine {
    /// The amount of force the engine can apply, measured in Newtons
    pub max_thrust_newtons: f64,

    #[reflect(ignore)]
    pub current_thrust_newtons: f64,
}

See also: https://crates.io/crates/bevy_reflect

Each field has the following parameters:

• "field" => the name. Needs to match with the rust struct field
• "type" => what type it is. Currently supported are "string", "bool", "f64", "f32", "int", "vec3", "vec2" and "u8enum"
• "default" => what value to use when the user hasn't set one yet. Note that for type "u8enum" this is instead an array of options for the user to pick from.
• "description" => help text for the user.

---

Be aware that the bevy rapier API has changed since I wrote this addon, so physics components probably won't work. Heck, it may not even compile into bevy. I haven't tried.

[Joe23232]

@sdfgeoff Hey man.

So I uninstalled the all addon and I installed the new addon.

What you put inside the JSON files depends on what components you have in your game.
Eg from the example above:

So I added this exact same script:

{
    "name": "Engine",
    "description": "Used to apply thrust to an object",
    "id": "space_ship_engine",
    "struct": "game::ship_parts::engine::Engine",
    "fields": [
        {
            "field": "max_thrust_newtons", 
            "type": "f64", 
            "default": 10.0,
            "description": "The max amount of force the engine can apply, measured in Newtons"
        }
    ]
}

into a file called windmill.json inside the folder component_definitions. In the outside directory of component_definitions I have a file called Demo.blend. And I still can't see any components to add.

not too sure why this is happening?

[Joe23232]

Starting a new thread at #11 @sdfgeoff