WARNING: BREAKING: REDESIGNED: **Animation System** #4606

REVIEWED: Reorganized structures for a clearer distinction between "skeleton", "skin" and "skinning" data
ADDED: New structures: `ModelSkeleton`, `ModelAnimPose` (alias `Transform*`)
ADDED: Runtime data `currentPose` and `boneMatrices` to `Model` structure
ADDED: Support animation frames-blending, for timing control
ADDED: Support animations blending, between two animations
REVIEWED: All models animation loading functions
ADDED: `UpdateModelAnimationEx()` for two animations blending
REMOVED: `UpdateModelAnimationBones*()`, simplified API
REVIEWED: Shader attributes/uniforms names for animations, for consistency
REVIEWED: Multiple tweaks on animations loading for consistency between formats
ADDED: example: `models_animation_timing`
ADDED: example: `models_animation_blending`
REVIEWED: example: `models_animation_gpu_skinning`
REVIEWED: example: `models_animation_blend_custom`
REVIEWED: All animated models loading examples

examples/models/models_animation_timing.c

@@ -0,0 +1,133 @@
+/*******************************************************************************************
+*
+*   raylib [models] example - animation timing
+*
+*   Example complexity rating: [★★☆☆] 2/4
+*
+*   Example originally created with raylib 5.6, last time updated with raylib 5.6
+*
+*   Example licensed under an unmodified zlib/libpng license, which is an OSI-certified,
+*   BSD-like license that allows static linking with closed source software
+*
+*   Copyright (c) 2026 Ramon Santamaria (@raysan5)
+*
+********************************************************************************************/
+
+#include "raylib.h"
+
+#define RAYGUI_IMPLEMENTATION
+#include "raygui.h"             // Required for: UI controls
+
+//------------------------------------------------------------------------------------
+// Program main entry point
+//------------------------------------------------------------------------------------
+int main(void)
+{
+    // Initialization
+    //--------------------------------------------------------------------------------------
+    const int screenWidth = 800;
+    const int screenHeight = 450;
+
+    InitWindow(screenWidth, screenHeight, "raylib [models] example - animation timing");
+
+    // Define the camera to look into our 3d world
+    Camera camera = { 0 };
+    camera.position = (Vector3){ 6.0f, 6.0f, 6.0f };    // 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 model
+    Model model = LoadModel("resources/models/gltf/robot.glb");
+    Vector3 position = { 0.0f, 0.0f, 0.0f }; // Set model world position
+
+    // Load model animations
+    int animCount = 0;
+    ModelAnimation *anims = LoadModelAnimations("resources/models/gltf/robot.glb", &animCount);
+
+    // Animation playing variables
+    int animIndex = 10;                  // Current animation playing
+    float animCurrentFrame = 0.0f;      // Current animation frame (supporting interpolated frames)
+    float animFrameSpeed = 0.5f;        // Animation play speed
+    bool animPause = false;             // Pause animation
+
+    // UI required variables
+    char *animNames[64] = { 0 };
+    for (int i = 0; i < animCount; i++) animNames[i] = anims[i].name;
+
+    bool dropdownEditMode = false;
+    float animFrameProgress = 0.0f;
+
+    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_ORBITAL);
+
+        if (IsKeyPressed(KEY_P)) animPause = !animPause;
+
+        if (!animPause && (animIndex < animCount))
+        {
+            // Update model animation
+            animCurrentFrame += animFrameSpeed;
+            if (animCurrentFrame >= anims[animIndex].keyframeCount) animCurrentFrame = 0.0f;
+            UpdateModelAnimation(model, anims[animIndex], animCurrentFrame);
+        }
+
+        // NOTE: Animation and playing speed selected through UI
+
+        // Update progressbar value with current frame
+        animFrameProgress = animCurrentFrame;
+        //----------------------------------------------------------------------------------
+
+        // Draw
+        //----------------------------------------------------------------------------------
+        BeginDrawing();
+
+            ClearBackground(RAYWHITE);
+
+            BeginMode3D(camera);
+
+                DrawModel(model, position, 1.0f, WHITE);
+            
+                DrawGrid(10, 1.0f);
+            
+            EndMode3D();
+
+            // Draw UI, select anim and playing speed
+            GuiSetStyle(DROPDOWNBOX, DROPDOWN_ITEMS_SPACING, 1);
+            if (GuiDropdownBox((Rectangle){ 10, 10, 140, 24 }, TextJoin(animNames, animCount, ";"), 
+                &animIndex, dropdownEditMode)) dropdownEditMode = !dropdownEditMode;
+
+            GuiSlider((Rectangle){ 260, 10, 500, 24 }, "FRAME SPEED: ", TextFormat("x%.1f", animFrameSpeed),
+                &animFrameSpeed, 0.1f, 2.0f);
+
+            // Draw playing timeline with keyframes
+            GuiLabel((Rectangle){ 10, GetScreenHeight() - 64, GetScreenWidth() - 20, 24 }, 
+                TextFormat("CURRENT FRAME: %.2f / %i", animFrameProgress, anims[animIndex].keyframeCount));
+            GuiProgressBar((Rectangle){ 10, GetScreenHeight() - 40, GetScreenWidth() - 20, 24 }, NULL, NULL,
+                &animFrameProgress, 0.0f, (float)anims[animIndex].keyframeCount);
+            for (int i = 0; i < anims[animIndex].keyframeCount; i++)
+                DrawRectangle(10 + ((float)(GetScreenWidth() - 20)/(float)anims[animIndex].keyframeCount)*(float)i, 
+                    GetScreenHeight() - 40, 1, 24, BLUE);
+
+        EndDrawing();
+        //----------------------------------------------------------------------------------
+    }
+
+    // De-Initialization
+    //--------------------------------------------------------------------------------------
+    UnloadModelAnimations(anims, animCount); // Unload model animation
+    UnloadModel(model);         // Unload model and meshes/material
+
+    CloseWindow();              // Close window and OpenGL context
+    //--------------------------------------------------------------------------------------
+
+    return 0;
+}
+