Applying texture displacement in Blender allows you to use a texture map to actually deform the geometry of your 3D model, creating real physical bumps and valleys rather than just simulating depth.
Texture displacement is a technique that uses a grayscale image (a displacement map) to tell a 3D program like Blender how to push or pull the vertices of a model. Dark areas typically represent lower points, and light areas represent higher points.
It's important to distinguish this from bump mapping or normal mapping.
- Bump Mapping: Simulates the appearance of bumps and wrinkles by altering how light reflects off the surface based on a texture, but it does not change the underlying geometry. It's an optical illusion.
- Normal Mapping: Similar to bump mapping, it uses a texture to store surface normal direction data, providing a more convincing illusion of detail than bump mapping, but still doesn't alter geometry.
- Displacement Mapping: Actually moves the vertices of the model based on the texture values, creating real physical changes to the shape. This requires a mesh with enough geometry (subdivisions) to displace effectively.
Here's a quick comparison:
| Feature | Bump Mapping | Normal Mapping | Displacement Mapping |
|---|---|---|---|
| Geometry | No change | No change | Changes geometry |
| Real Depth | No | No | Yes |
| Silhouette | Flat | Flat | Changes silhouette |
| Detail Level | Lower illusion | Higher illusion | Highest (real) |
How to Apply Texture Displacement in Blender
Applying displacement in Blender typically involves enabling the feature in your material settings or using a modifier, and ensuring your model has sufficient geometry.
Method 1: Using Material Settings (Cycles/Eevee)
This is the most common method for rendering with Cycles or Eevee.
- Ensure Enough Geometry: Your model needs subdivisions to displace. Add a Subdivision Surface modifier (Shift+A > Modifier > Generate > Subdivision Surface) and set the 'Levels Viewport' and 'Render' values high enough (e.g., 4-6 or more, depending on desired detail and performance). Ensure the modifier is applied before displacement takes effect if using a modifier-based displacement, or ensure adaptive subdivision is enabled in Cycles for render time displacement.
- Prepare Your Material:
- Go to the Shader Editor (Shift+F3 or select from top-left dropdown).
- Ensure you have a material assigned to your object (e.g., a Principled BSDF).
- Enable Displacement in Material Settings:
- In the Properties Panel (usually on the right, press N if hidden), go to the Material Properties tab (the red sphere icon).
- Scroll down to the Settings rollout.
- Under Surface, find the "Displacement" option.
- Change this setting from "Bump Only" to "Displacement Only" or "Displacement and Bump". "Displacement and Bump" is often preferred as it combines the geometric displacement with finer bump details from the same or a different map.
- Add the Displacement Node in Shader Editor:
- In the Shader Editor, add a Displacement node (Shift+A > Vector > Displacement).
- Connect the Displacement node's output to the Displacement input on the Material Output node.
- Add an Image Texture node (Shift+A > Texture > Image Texture) and open your displacement map (usually a grayscale .exr, .tif, or .png).
- Connect the Color output of the Image Texture node to the Height input of the Displacement node.
- Important: For linear displacement data (like most displacement maps), the Image Texture node's Color Space should be set to "Non-Color".
- Adjust Displacement: On the Displacement node, you can adjust the 'Strength' to control the magnitude of the displacement and the 'Midlevel' to control the zero point (where no displacement occurs). A common Midlevel value is 0.5 for maps where gray (0.5) means no displacement, black (0) means push in, and white (1) means push out.
Method 2: Using the Displacement Modifier
This method applies displacement as a modifier in the stack, which can be useful for specific workflows or older rendering engines.
- Ensure Enough Geometry: Again, sufficient geometry is crucial. Add a Subdivision Surface modifier before the Displacement modifier in the stack.
- Add the Displacement Modifier: Select your object, go to the Modifier Properties tab (the blue wrench icon). Add a Displace modifier (Shift+A > Modifier > Deform > Displace).
- Create or Select a Texture:
- In the Displace modifier settings, click the 'New' button to create a new texture, or select an existing one from the dropdown.
- Click the Texture Properties tab (the checkerboard icon) to configure the texture you just created or selected.
- Under the 'Image' or 'Movie' settings, click 'Open' to load your displacement map image file.
- Configure Displacement in Modifier:
- Go back to the Modifier Properties tab.
- Adjust the 'Strength' of the modifier. Positive values displace outwards, negative values inwards.
- Adjust the 'Midlevel' if needed (often 0.5 for grayscale displacement maps).
- You can also choose the 'Direction' (e.g., Normal, X, Y, Z). 'Normal' is common.
Method 3: As Shown in the Reference
The provided reference describes a specific set of steps:
- Press n
- In the window that appears click options settings.
- And change bump only to displacement on bump.
Based on the video snippet, this refers to accessing a sidebar panel (likely the 'N' panel in the 3D Viewport or Shader Editor) to find "options settings" and changing a toggle or dropdown related to displacement, specifically switching from a "bump only" mode to one that includes displacement. This setting might be found within the Material Properties settings accessible via the 'N' panel in certain contexts, or within texture influence settings depending on the Blender version or specific workflow being used.
Key Considerations for Effective Displacement
- Geometry is King: Displacement needs vertices to push around. Without enough subdivisions (either from a modifier or adaptive subdivision in Cycles), you won't see smooth, detailed displacement.
- Texture Quality: Use high-resolution, 32-bit floating-point displacement maps (like EXR or TIFF) for the best results, as they store more precise height information. 8-bit images can cause banding.
- Strength and Midlevel: Experiment with these values on the Displacement node or modifier to get the desired height and depth.
- Subdivision Order: If using the modifier stack, the Subdivision Surface modifier must come before the Displace modifier.
By following these steps, you can successfully apply texture displacement in Blender to add realistic surface detail that goes beyond the illusion of bump or normal mapping.
