Rendering Loop

Rendering Loop

To verify the model is working, you need to update its state and draw it every frame. This typically happens inside your main game loop (e.g., GLFW loop).

The Update Step

The update method advances the physics, fades motions, and calculates the new positions of all vertices.

// deltaTime: Time in seconds since the last frame (e.g., 0.016 for 60fps)
model.update(deltaTime);

Warning: Do not pass 0 as delta time, as physics calculations may behave unpredictably.

The Draw Step

The draw method requires a Model-View-Projection (MVP) matrix to position the model on your screen.

// A simple 4x4 Identity Matrix (Float array of size 16)
float[] mvpMatrix = new float[] {
    1, 0, 0, 0,
    0, 1, 0, 0,
    0, 0, 1, 0,
    0, 0, 0, 1
};

// Adjust for aspect ratio so the model doesn't look stretched
float aspect = (float) windowWidth / windowHeight;
mvpMatrix[0] = 1.0f / aspect; // Scale X by 1/aspect

model.draw(mvpMatrix);

Vulkan-specific draw target update

If you are using Vulkan, set current frame render target before draw:

model.setVulkanRenderTarget(vkImage, vkImageView, vkFormat, width, height);
model.draw(mvpMatrix);

Context Awareness

model.draw() calls OpenGL functions (glDrawElements, glBindTexture, etc.). Therefore, it must be called from the thread that holds the OpenGL context. For Vulkan, call it on the thread that owns/records the active Vulkan command flow for that frame.