[rmodels] Errors during LoadMesh on MacOS

[TillWege]

Issue description

Since #4321 uploading Meshes on MacOS will randomly fail and cause the running program to crash.

Environment

• MacBook Pro M1 16gb running MacOS 15

Issue Screenshot

Code Example

#define MODEL_FOLDER "models/"

int main()
{
	const int screenWidth = 1280;
	const int screenHeight = 720;

	InitWindow(screenWidth, screenHeight, "Window");

	std::vector<Model> models;

	for (const auto& entry : std::filesystem::directory_iterator(MODEL_FOLDER)) {
		std::string path = entry.path().string();
		std::string fileName = entry.path().filename().string();
		if (IsFileExtension(fileName.c_str(), ".obj")) {
			Model model = LoadModel(path.c_str());
			models.push_back(model);
		}
	}
}

Running this leads to it crashing within the first ~4 models it tries to load. It doesn't seem to change whether its .obj or .gltf files.

[JeffM2501]

It's possible that the mac may only support 8 VBOs, the code should check GL for the max and not try to load them all if possible.
We may need to tie the GPU skinning feature to a flag that apple platforms do not set, or perhaps remove one of the other less used VBOs

[deDug]

This could be the same problem as #4343. When loading mesh a bad define can mean the wrong amount of memory is allocated for VBO indices.
You could try changing MAX_MESH_VERTEX_BUFFERS in config.h to 9 and see if that fixes it.

[TillWege]

Yeah you seem to be right. When I change it to 7 the crash doesnt appear.

[JeffM2501]

I just tested on an intel mac, and can verify that yes, the mac only supports 8 VBOs.
We will have to not support GPU meshes on the mac, and move those buffers to the end.
This includes meshes that don't even use animations, the change to use 9 VBOs just strait up breaks meshes on Mac OS.

[JeffM2501]

PR #4348 should disable this feature for MacOS

[stevegwh]

@raysan5 @JeffM2501 Not sure if this is the place to put this but: GPU Skinning (#4321) works fine for me on macOS (Sonoma 14.6.1) (M1 MacBook Air 2020) after changing "MAX_MESH_VERTEX_BUFFERS" to 9 in config.h. This is using the example and model from "models_gpu_skinning.c" (I'll include it below, also). So, at least on my machine, macOS seems to support GPU skinning and all other models that I have tried load fine. Unless I've misunderstood, something.

I'm happy to test more things out if you want.

EDIT:
Here is some more info:

INFO: GL: Supported extensions count: 43
INFO: GL: OpenGL device information:
INFO:     > Vendor:   Apple
INFO:     > Renderer: Apple M1
INFO:     > Version:  4.1 Metal - 88.1
INFO:     > GLSL:     4.10`

// models_gpu_skinning.c

#include "raylib.h"

#include "raymath.h"

#if defined(PLATFORM_DESKTOP)
    #define GLSL_VERSION            330
#else   // PLATFORM_ANDROID, PLATFORM_WEB
    #define GLSL_VERSION            100
#endif

//------------------------------------------------------------------------------------
// Program main entry point
//------------------------------------------------------------------------------------
int main(void)
{
    // Initialization
    //--------------------------------------------------------------------------------------
    const int screenWidth = 800;
    const int screenHeight = 450;

    InitWindow(screenWidth, screenHeight, "raylib [models] example - GPU skinning");

    // Define the camera to look into our 3d world
    Camera camera = { 0 };
    camera.position = (Vector3){ 5.0f, 5.0f, 5.0f }; // Camera position
    camera.target = (Vector3){ 0.0f, 2.0f, 0.0f };  // Camera looking at point
    camera.up = (Vector3){ 0.0f, 1.0f, 0.0f };      // Camera up vector (rotation towards target)
    camera.fovy = 45.0f;                            // Camera field-of-view Y
    camera.projection = CAMERA_PERSPECTIVE;         // Camera projection type

    // Load gltf model
    Model characterModel = LoadModel("resources/models/gltf/greenman.glb"); // Load character model
    
    // Load skinning shader
    Shader skinningShader = LoadShader(TextFormat("resources/shaders/glsl%i/skinning.vs", GLSL_VERSION),
                                       TextFormat("resources/shaders/glsl%i/skinning.fs", GLSL_VERSION));
    
    characterModel.materials[1].shader = skinningShader;
    
    // Load gltf model animations
    int animsCount = 0;
    unsigned int animIndex = 0;
    unsigned int animCurrentFrame = 0;
    ModelAnimation *modelAnimations = LoadModelAnimations("resources/models/gltf/greenman.glb", &animsCount);

    Vector3 position = { 0.0f, 0.0f, 0.0f }; // Set model position

    DisableCursor();                    // Limit cursor to relative movement inside the window

    SetTargetFPS(60);                   // Set our game to run at 60 frames-per-second
    //--------------------------------------------------------------------------------------

    // Main game loop
    while (!WindowShouldClose())        // Detect window close button or ESC key
    {
        // Update
        //----------------------------------------------------------------------------------
        UpdateCamera(&camera, CAMERA_THIRD_PERSON);
        
        // Select current animation
        if (IsKeyPressed(KEY_T)) animIndex = (animIndex + 1)%animsCount;
        else if (IsKeyPressed(KEY_G)) animIndex = (animIndex + animsCount - 1)%animsCount;

        // Update model animation
        ModelAnimation anim = modelAnimations[animIndex];
        animCurrentFrame = (animCurrentFrame + 1)%anim.frameCount;
        UpdateModelAnimationBoneMatrices(characterModel, anim, animCurrentFrame);
        //----------------------------------------------------------------------------------

        // Draw
        //----------------------------------------------------------------------------------
        BeginDrawing();

            ClearBackground(RAYWHITE);

            BeginMode3D(camera);
            
                // Draw character
                characterModel.transform = MatrixTranslate(position.x, position.y, position.z);
                UpdateModelAnimationBoneMatrices(characterModel, anim, animCurrentFrame);
                DrawMesh(characterModel.meshes[0], characterModel.materials[1], characterModel.transform);

                DrawGrid(10, 1.0f);
            EndMode3D();

            DrawText("Use the T/G to switch animation", 10, 10, 20, GRAY);

        EndDrawing();
        //----------------------------------------------------------------------------------
    }

    // De-Initialization
    //--------------------------------------------------------------------------------------
    UnloadModelAnimations(modelAnimations, animsCount);
    UnloadModel(characterModel);         // Unload character model and meshes/material
    UnloadShader(skinningShader);
    
    CloseWindow();              // Close window and OpenGL context
    //--------------------------------------------------------------------------------------

    return 0;
}

[JeffM2501]

@raysan5 @JeffM2501 Not sure if this is the place to put this but: GPU Skinning (#4321) works fine for me on macOS (Sonoma 14.6.1) (M1 MacBook Air 2020) after changing "MAX_MESH_VERTEX_BUFFERS" to 9 in config.h. This is using the example and model from "models_gpu_skinning.c" (I'll include it below, also). So, at least on my machine, macOS seems to support GPU skinning and all other models that I have tried load fine. Unless I've misunderstood, something.

I'm going to try this with the config fix and see if that is the issue.

[stevegwh]

@JeffM2501 Cool. You can see here for the logic behind it: #4349
HarryDC's comment (can't tag him, for some reason): "This is the model i used to check, the issue is most likely a MAX_MESH_VERTEX_BUFFERS definition in config.h line 231 that is 7, whereas the value needs to be 9 as defined in line 123 in rmodels.c"

Once I changed MAX_MESH_VERTEX_BUFFERS to 9 in config.h, models loaded fine and I've been using GPU skinning on macOS without issue since then.

[JeffM2501]

Yeah that was the issue, it does work on the mac. I have summited PR#4353 that should get it all in line.