From Classic to Dynamic

An interactive guide to understanding the shift from `VkRenderPass` to Dynamic Rendering in Vulkan 1.3.

Paradigm Comparison

A side-by-side look at the core architectural differences.

Classic Paradigm (`VkRenderPass`)

The original Vulkan 1.0 model, built on heavyweight, pre-configured objects. It's powerful but rigid, defining the entire render structure upfront.

Core Concepts

Relies on `VkRenderPass` to define attachments and subpasses, and `VkFramebuffer` to bind actual images. Pipelines are compiled against a specific `VkRenderPass`.

Synchronization

Largely **implicit**. Image layout transitions are handled automatically by the driver based on `initialLayout` and `finalLayout` in the render pass definition.

Key Strength

Subpasses enable high-efficiency techniques like deferred rendering on tile-based GPUs (common in mobile) by keeping data in fast on-chip memory.

Architectural Friction

Leads to a "combinatorial explosion" of pipeline and render pass objects when supporting different formats or MSAA levels, increasing complexity.

Modern Paradigm (Dynamic Rendering)

Introduced in Vulkan 1.3, this model is flexible and imperative, defining render state at command recording time.

Core Concepts

Uses `vkCmdBegin/EndRendering` with transient info structs. `VkRenderPass` and `VkFramebuffer` objects are eliminated for single-pass rendering.

Synchronization

Fully **explicit**. The developer is responsible for inserting pipeline barriers (`vkCmdPipelineBarrier`) to transition image layouts as needed.

Key Strength

Massively improved flexibility and reduced boilerplate. Decouples pipelines from render targets, simplifying engine architecture.

Modern Solution

The `VK_KHR_dynamic_rendering_local_read` extension provides the performance benefits of subpasses within the new, flexible model.

Visualizing the Workflow Shift

Classic Workflow
1. Create `VkRenderPass` (Heap Object)
↓
2. Create `VkFramebuffer` (Heap Object)
↓
3. `vkCmdBeginRenderPass()`
Implicit layout transition to `COLOR_ATTACHMENT_OPTIMAL`
↓
4. `vkCmdDraw()`
↓
5. `vkCmdEndRenderPass()`
Implicit layout transition to `PRESENT_SRC_KHR`
Dynamic Rendering Workflow
1. **Explicit `vkCmdPipelineBarrier`**
Transition to `COLOR_ATTACHMENT_OPTIMAL`
↓
2. `vkCmdBeginRendering()` (Stack Structs)
↓
3. `vkCmdDraw()`
↓
4. `vkCmdEndRendering()`
↓
5. **Explicit `vkCmdPipelineBarrier`**
Transition to `PRESENT_SRC_KHR`

Interactive Code Migration

See how the code changes in practice. Select a function to view the refactoring.

Before (Classic `VkRenderPass`)

After (Dynamic Rendering)

Impact Analysis & Recommendations

Why does this change matter? A look at performance, architecture, and best practices.

Paradigm Trade-offs

A visual comparison of key architectural attributes. Higher values are generally better.

The Modern Vulkan Ecosystem

Dynamic Rendering isn't an isolated feature. It's a key part of a trio of Vulkan 1.3+ features designed to reduce pipeline churn and increase flexibility.

1

Dynamic Rendering

Decouples pipelines from `VkRenderPass` objects.

2

Extended Dynamic State

Decouples pipelines from fixed state like cull mode, depth testing, etc.

3

Synchronization2

Simplifies and clarifies the explicit synchronization required by the new model.

Final Recommendation

For any modern application targeting Vulkan 1.3-capable hardware, **Dynamic Rendering should be the default rendering path.** Its benefits in code simplicity and architectural flexibility are substantial. The classic `VkRenderPass` model should be reserved for legacy hardware compatibility or niche multi-subpass scenarios where modern extensions are unavailable.