Bake High-Poly to Low-Poly Mesh in Blender

Baking high-poly sculpt details onto a low-poly mesh is a fundamental workflow in 3D modeling that allows you to retain intricate details while keeping your model optimized for games and real-time engines. This step-by-step guide covers how to prepare your meshes, configure Blender's Cycles engine for baking, and generate a clean normal map.

Step 1: Prepare Your Meshes

Before baking, you must ensure both models are properly positioned and prepared:

  1. Align the Meshes: Place your high-poly and low-poly meshes at the exact same coordinates in 3D space.
  2. UV Unwrap the Low-Poly Mesh: The low-poly mesh must have a clean, non-overlapping UV map. The high-poly mesh does not require UV coordinates.
  3. Smooth Shading: Right-click the low-poly mesh and select Shade Auto Smooth or Shade Smooth to ensure the normal map calculates transitions correctly.

Step 2: Create a Target Texture

You need an image texture to store the baked normal map details:

  1. Select your low-poly mesh and go to the Material Properties tab.
  2. Assign a material to the low-poly mesh if it does not have one.
  3. Open the Shader Editor workspace.
  4. Press Shift + A, search for Image Texture, and place the node in the graph. Do not connect it to any other node yet.
  5. Click New on the Image Texture node. Name it "Normal_Map", set your desired resolution (e.g., 2048 x 2048), and click OK.
  6. Ensure this Image Texture node remains selected (highlighted with a white border). This tells Blender where to save the baked data.

Step 3: Configure the Render Engine

Blender's default renderer, Eevee, does not support baking. You must switch to Cycles:

  1. Go to the Render Properties tab (camera icon) on the right side of the screen.
  2. Change the Render Engine from Eevee to Cycles.
  3. Set the Device to GPU Compute for faster baking times if you have a compatible graphics card.

Step 4: Set Up the Bake Panel

With Cycles active, scroll down in the Render Properties tab to locate the Bake panel:

  1. Change the Bake Type to Normal.
  2. Check the box for Selected to Active.
  3. Expand the Selected to Active dropdown menu.
  4. Set the Extrusion value. A value between 0.01m and 0.1m is usually ideal. This determines how far outwards Blender casts rays to find the high-poly surface.

Step 5: Bake the Normal Map

The selection order is critical for the "Selected to Active" function to work:

  1. In the 3D Viewport, select the high-poly mesh first.
  2. Hold Shift and select the low-poly mesh second. The low-poly mesh should have a light orange outline, indicating it is the active selection.
  3. Verify that the Image Texture node you created in Step 2 is still highlighted/selected in the Shader Editor.
  4. Go to the Bake panel and click the Bake button.
  5. Wait for the progress bar at the bottom of the screen to reach 100%.

Step 6: Save and Apply the Normal Map

Once the bake is complete, you must save the image file:

  1. Open the Image Editor workspace and select your baked normal map from the dropdown list.
  2. Click Image > Save As and save the file to your computer.
  3. In the Shader Editor, change the Color Space of your Image Texture node from SRGB to Non-Color.
  4. Press Shift + A, search for a Normal Map node, and place it.
  5. Connect the Color output of the Image Texture to the Color input of the Normal Map node.
  6. Connect the Normal output of the Normal Map node to the Normal input of your Principled BSDF shader.