# Geometry attributes
Intermediate
Artist
Programmer
The material **geometry** attributes define the shape of a material.
## Tessellation
Real-time tessellation uses a HW feature of the GPU to massively subdivide triangles. This increases the realism and potential of deformations of the surface geometry.
You can choose **none**, **flat tessellation**, or **point normal tessellation**.
| No tessellation | Flat tessellation | Point normal tessellation
| -------------- | -------------- | --------------------
|  |  | 
### Flat tessellation
This option tessellates the mesh uniformly.
In the images below, notice how the flat tessellation adds extra triangles, but doesn't take the curve into account:
| No tessellation | Flat tessellation
| ---------------- | -----------------
|  | 
| Property | Description
| ---------------------- | ------------
| Triangle size | The size of a tessellated triangle in screen-space units
| Adjacent edges average | Adjust the triangle size values from the average of adjacent edges values
### Point normal tessellation
This option tessellates the mesh using the curvature provided by the mesh normals.
The images below show how point normal tessellation adds extra triangles while taking the curvature of the mesh into account:
| No tessellation | Point normal tessellation
| ---------------| ---------------------- |
|  |
| Property | Description
| ---------------------- | ------------
| Triangle size | The size of a tessellated triangle in screen-space units
| Adjacent edge average | Adjust the **triangle size** and **normal curvature** values from the average of adjacent edge values
## Displacement
Under the **Displacement** properties, you can specify **displacement map**. This displaces the geometry of the mesh.
Depending on the stage at which the displacement is applied, the results can be very different:
| Displacement with vertex shader | Tessellation with displacement
| ------| ----------------- |
|  | 
| Property | Description
| ---------------- | ------------
| Displacement Map | The displacement texture as a [material color provider](material-maps.md)
| Intensity | The amount of displacement
| Scale & Bias | When enabled, the value coming from the texture is considered a positive value ranging from `0.0` to `1.0` and the shader applies a scale to get the range -1.0 to `1.0`
| Shader Stage | Specify which shader stage the displacement map should be applied to: vertex shader or domain shader (used with tessellation)
## Surface
Under the **Surface** properties, you can define a [Normal maps](../textures/normal-maps.md) to define **macro** surface normals. The **normal map** provides per-pixel normal perturbation of the normal of the mesh. Normal maps create the appearance of bumps and indents in the mesh:
| Flat | Using a normal map
| -----| -----------
|  | 
| Property | Description
| ------------ | ---------------
| Normal map | The normal map color provider
| Scale and offset | Interpret values from the texture as positive values ranging from `0.0` to `1.0`. The shader applies a scale to get the range `-1.0` to `1.0`.
| Reconstruct Z | If there's no Z component in the texture, reconstruct it from the X and Y components. This assumes that X2 + Y2 + Z2 = 1 and that Z is always positive, so no normal vector can point to the back side of the surface. We recommend you enable this option, as Stride might remove the Z component when you compress normal maps.
For more information about normal maps, see the [normal maps](../textures/normal-maps.md) page.
## Micro surface
Under the **Micro surface** setting, you can provide a **gloss map** to provide per-pixel information for gloss.
If you select **Float**:
- a value of `1.0` means the surface is highly glossy (the coarse normal isn't perturbed)
- a value of `0.0` means the surface is very rough (the coarse normal is highly perturbed in several directions)
The screenshots below show different levels of gloss on a material:
- Diffuse = #848484, Lambert
- Specular Metalness = 1.0, GGX
| Gloss = 0.0 | 0.25 | 0.5 | 0.8 | 1.0
| ---------------- | ---- | ---- |----- | ---
|  |  |  |  | 
| Property | Description
| -------------- | -- |
| Gloss map | The gloss map color provider
| Invert | Inverts the gloss value (eg a value of `1.0` produces zero gloss instead of maximum). This effectively turns the gloss value into a **roughness** value, as used in other game engines
If you have local reflections enabled, the scene is reflected in materials with a gloss map value higher than the threshold you specify in the local reflections properties. For more information, see [Local reflections](../post-effects/local-reflections.md).
## See also
* [Material maps](material-maps.md)
* [Material attributes](material-attributes.md)
* [Shading attributes](shading-attributes.md)
* [Misc attributes](misc-attributes.md)
* [Clear-coat shading](clear-coat-shading.md)
* [Clear-coating shading](clear-coat-shading.md)
* [Material layers](material-layers.md)
* [Material slots](material-slots.md)
* [Materials for developers](materials-for-developers.md)
* [Custom shaders](../effects-and-shaders/custom-shaders.md)