How to reuse same model with different animations?

[tymbaca]

Upd. I use odin-lang and raylib v5.5

Hi! I'm struggling with raylib 3d animations. I want to draw multiple instances of model, but with different animations. But no matter what i do, they always play the same animation. Here is the code snippet:

Context :: struct {
        player: ecs.Entity,
        cam:    rl.Camera3D,
        cursor_enabled:  bool,

        models:            [Model_Kind]rl.Model,
        model_anim_counts: [Model_Kind]i32,
        model_anims:       [Model_Kind][^]rl.ModelAnimation,
}

Model_Kind :: enum {
        Double_Barrel,
}

main :: proc() {        
        // ...
        
        rl.SetConfigFlags({.WINDOW_RESIZABLE})
        rl.InitWindow(SCREEN_WIDTH, SCREEN_HEIGHT, "kidnapper")
        rl.DisableCursor()
        rl.SetTargetFPS(120)

        cam: rl.Camera3D
        cam.up = {0, 1, 0}
        cam.fovy = 80
        cam.projection = .PERSPECTIVE
        cam.target = {0, 0, 0}
        cam.position = {0, 0, -5}
        ctx.cam = cam

        ctx.models = {
                .Double_Barrel = rl.LoadModel("resources/gun.m3d"),
        }
        ctx.model_anims = {
                .Double_Barrel = rl.LoadModelAnimations("resources/gun.m3d", &ctx.model_anim_counts[.Double_Barrel]),
        }

        anim_count: c.int
        anims := rl.LoadModelAnimations("resources/gun.m3d", &anim_count)

        anim_index :: 0
        anim_frame: i32

        for !rl.WindowShouldClose() {
                anim_frame = (anim_frame + 1) % anims[anim_index].frameCount

                rl.BeginDrawing()
                rl.ClearBackground(rl.DARKGRAY)
                rl.BeginMode3D(ctx.cam)

                rl.UpdateModelAnimation(ctx.models[.Double_Barrel], anims[DOUBLE_BARRED_READY_ANIM], 0)
                rl.DrawModel(ctx.models[.Double_Barrel], {1, 1, 1}, 1, rl.WHITE)
                rl.UpdateModelAnimation(ctx.models[.Double_Barrel], anims[DOUBLE_BARRED_FIRE_ANIM], anim_frame)
                rl.DrawModel(ctx.models[.Double_Barrel], {2, 1, 1}, 1, rl.WHITE)

                rl.DrawBoundingBox(rl.GetModelBoundingBox(ctx.models[.Double_Barrel]), rl.RED)

                rl.EndMode3D()
                rl.DrawFPS(10, 10)
                rl.EndDrawing()
        }
}

[mcthomas]

I think you need one model instance per independently-animated instance. Have you been able to make progress since posting this?

[tymbaca]

after posting i switch to the approach of using a one obj file per frame, manually selecting obj file for specific frame

[dc1248]

Yes, you need separate Models for independent animations. That's not changing in 6.0 which is coming very soon.

You CAN copy the Model and allocate new boneMatrices for each copy. It's not optimal though. The copies will share the same mesh/material data, but Raylib will upload each copy to the GPU separately, wasting VRAM and time. Raylib's 3D system is somewhat beginner-oriented. Maybe that'll change eventually but not in 6.0.

[tymbaca]

thanks! do i understand correctly that if LoadModel for each instance of my model, model data will be duplicated in gpu memory?

[dc1248]

Yes. You should do a stress test to see how many separate animated model instances you can have on screen at a good framerate. And monitor your VRAM usage as you increase the model count.