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MeshLoader

MeshLoader is a lightweight C# library designed for MelonLoader mods, allowing you to load custom 3D meshes and textures from base64-encoded strings in Unity games. The library uses Unity's Universal Render Pipeline (URP) to apply textures and provides two simple static methods to load a Mesh and a Matereal with a custom texture, making it easy to add dynamic assets to your MelonLoader mods.

Note: MeshLoader is built for MelonLoader mods and currently supports URP only. Support for other render pipelines may be added in future updates.

Features

Load 3D meshes from base64-encoded OBJ files.
Load textures from base64-encoded images (e.g., PNG, JPEG) and apply them to a URP/Lit material.
Lightweight and easy to integrate into MelonLoader mods.
Error handling with detailed logging for debugging via MelonLoader.

Installation

Prerequisites

MelonLoader: Install MelonLoader (version 0.5.x or 0.6.x recommended). Follow their installation guide for setup.
Game with URP: Ensure the Unity game you're modding uses the Universal Render Pipeline (URP).
.NET Framework: The library is built with .NET Framework for Unity/MelonLoader compatibility.

Steps

1. Download the DLL:

Download MeshLoader.dll from the Releases page of it's repository.

2. Add to Your MelonLoader Mod:

Place MeshLoader.dll in the Plugins folder of your game directory (e.g., GameFolder/Plugins/MeshLoader.dll).
Alternatively, if your mod has its own folder (e.g., GameFolder/Mods/YourMod), place it in GameFolder/Mods/YourMod/Plugins/MeshLoader.dll.

3. Verify Setup:

Run your game with MelonLoader and check the MelonLoader log (GameFolder/MelonLoader/Latest.log) to ensure the DLL loads without errors.

Usage

MeshLoader provides two static methods under the MeshLoader namespace: GetCustomMesh and GetCustomTexture. These methods allow you to load a mesh and a material with a custom texture directly from base64 strings in your MelonLoader mod.

Example: Loading a Mesh and Texture in a MelonLoader Mod

Below is an example of how to use MeshLoader in a MelonLoader mod to load a custom mesh and texture into a scene:


using MelonLoader;
using UnityEngine;
using MeshLoader;

public class MyMod : MelonMod
{
    public override void OnSceneWasLoaded(int buildIndex, string sceneName)
    {
        MelonLogger.Msg($"Scene: {sceneName} Was Loaded");

        if (sceneName == "Menu")
        {
            // Replace these with your actual base64-encoded strings
            string base64Mesh = "/* Your base64-encoded OBJ string */";
            string base64Texture = "/* Your base64-encoded image string */";

            // Load the mesh and material
            Mesh mesh = MeshLoaderUtility.GetCustomMesh(base64Mesh);
            Material material = MeshLoaderUtility.GetCustomTexture(base64Texture);

            if (mesh != null && material != null)
            {
                // Create a GameObject to display the mesh
                GameObject meshObject = new GameObject("CustomMesh");
                meshObject.layer = LayerMask.NameToLayer("Default");
                MeshFilter meshFilter = meshObject.AddComponent();
                MeshRenderer meshRenderer = meshObject.AddComponent();
                meshFilter.mesh = mesh;
                meshRenderer.material = material;

                MelonLogger.Msg("Custom mesh and material loaded successfully!");
            }
            else
            {
                MelonLogger.Msg("Failed to load mesh or material.");
            }
        }
    }
}

API Reference

`MeshLoaderUtility.GetCustomMesh(string base64)`

Description: Loads a 3D mesh from a base64-encoded OBJ file string.

Parameters:

base64: A base64-encoded string representing an OBJ file

on this page you can base64-encode files

Returns:

UnityEngine.Mesh: The loaded mesh, or null if an error occurs.

Example:


Mesh mesh = MeshLoaderUtility.GetCustomMesh("YourBase64String");
if (mesh != null)
{
    MelonLogger.Msg("Mesh loaded successfully!");
}

`MeshLoaderUtility.GetCustomTexture(string base64)`

Description: Loads a texture from a base64-encoded image (e.g., PNG, JPEG) and applies it to a URP/Lit material.

Parameters:

base64: A base64-encoded string representing an image file.

Returns:

UnityEngine.Material: A material with the "Universal Render Pipeline/Lit" shader and the loaded texture applied, or null if an error occurs. Falls back to the "Standard" shader if URP/Lit is unavailable.

Example:


Material material = MeshLoaderUtility.GetCustomTexture("YourBase64Texture");
if (material != null)
{
    MelonLogger.Msg("Material with texture loaded successfully!");
}

Limitations

Designed specifically for MelonLoader mods; not intended for standalone Unity projects.

Currently supports Universal Render Pipeline (URP) only. If URP is not set up in the game, the library falls back to the "Standard" shader, which may not render correctly.

The OBJ parser assumes a basic format (vertices, UVs, and faces). Complex OBJ features (e.g., materials, smoothing groups) are not supported.

Base64 strings must be valid and correctly encoded (OBJ for meshes, image formats like PNG/JPEG for textures).

Troubleshooting

DLL Not Found: Ensure MeshLoader.dll is in the correct folder (GameFolder/Plugins or GameFolder/Mods/YourMod/Plugins).

TypeLoadException: Verify the DLL name (MeshLoader.dll, no spaces) and ensure the namespace (MeshLoader) is correctly imported.

Shader Issues: Confirm the game you're modding uses URP. If the "Universal Render Pipeline/Lit" shader is not found, check the game's render pipeline setup.

MelonLoader Logs: Check GameFolder/MelonLoader/Latest.log for detailed error messages.