https://github.com/selimanac/defold-blender-convex-hull

https://github.com/selimanac/defold-blender-convex-hull

Last synced: about 2 months ago
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• Host: GitHub
• URL: https://github.com/selimanac/defold-blender-convex-hull
• Owner: selimanac
• Created: 2024-07-23T12:12:08.000Z (6 months ago)
• Default Branch: main
• Last Pushed: 2024-07-24T06:00:21.000Z (6 months ago)
• Last Synced: 2024-11-26T21:36:08.898Z (2 months ago)
• Language: Python
• Size: 562 KB
• Stars: 4
• Watchers: 1
• Forks: 0
• Open Issues: 0
• Metadata Files:
  • Readme: README.md
  • Funding: .github/FUNDING.yml

Awesome Lists containing this project

• awesome-defold - defold-blender-convex-hull

README

        
# Creating Convex Hull in Blender

This small script is tested with Blender 4.1.1. It might not work any older versions.  

You can find the example Blender project and Python Scripts in the `blender` [folder](https://github.com/selimanac/defold-blender-convexhull/tree/main/blender) of this repo.  

Defold project contains example [Convex hull](https://defold.com/manuals/physics-shapes/#convex-hull-shape) shapes.  

### Create Convex Hull in Blender:

- Load your model and prepare it for [importing Defold](https://defold.com/manuals/importing-models/#using-a-model).   

- If you want to match the transform of your model and convex hull, disable the `+Y Up` option in the **Transform** section of the export window.

![+Y Up](/.github/6.png?raw=true)

- Select the model/object and switch to `Edit Mode` (`Tab`).  

![Edit Mode](/.github/1.jpg?raw=true)

- Select all vertices (`A`).    

![Select all vertices](/.github/2.jpg?raw=true)

- Use the "Convex Hull" operation (press F3, search for "Convex Hull") or select "Mesh" -> "Convex Hull" from menu.   

![Convex Hull](/.github/3.jpg?raw=true)

### Export Convex Hull Points Using Python Script:

- Go to the Scripting tab or open a new `Text Editor` in Blender.  

![Text Editor](/.github/4.jpg?raw=true)

- Copy and paste [the script](https://github.com/selimanac/defold-blender-convexhull/blob/main/blender/convexshape.py) into the scripting editor.   

- Adjust the `export_path` variable to the desired file path where you want to save the exported convex hull data.   

- Ensure the correct object is **selected**.     

- Click the `Run Script` button in the scripting editor.  

![Run Scrip](/.github/5.jpg?raw=true)

This should correctly export the convex hull data to the specified file.  

```python

import bpy

import bmesh

import os

def export_convex_hull_points(obj, filepath):

    # Create a new bmesh and fill it with the object's mesh data

    bm = bmesh.new()

    bm.from_mesh(obj.data)

    # Create the convex hull

    bmesh.ops.convex_hull(bm, input=bm.verts)

    # Extract vertices from the convex hull

    vertices = [v.co.copy() for v in bm.verts]

    # Write to file

    with open(filepath, 'w') as f:

        f.write(f"shape_type: TYPE_HULL\n")

        for v in vertices:

            f.write(f"data: {v.x}\n")

            f.write(f"data: {v.y}\n")

            f.write(f"data: {v.z}\n")

    # Free the bmesh

    bm.free()

# Ensure the correct object is selected

obj = bpy.context.object

# Specify the export path

# Default is .blender file's folder

export_path =  os.path.join(bpy.path.abspath("//"), "file_name.convexshape")

# Export the convex hull points

export_convex_hull_points(obj, export_path)

print(f"Convex hull points exported to {export_path}")

```