Materials

Materials are what you apply to an object in order to make it look or behave like something in the real world. Materials are one of the key components of a table, because they define the visuals and the physical behavior. However, the term material can be confusing, because it can have different meanings. So let's define them first.

Rendered Materials

We refer to rendered materials just as materials. They describe how a surface of a mesh is drawn on the sceen. In Unity, materials and shaders are closely linked - every material uses a shader, which you can configure. The most common shader is the Lit shader, which works well for rigid materials that interact with light.

A material typically includes one or more textures that define the color, normals, roughness, metalness and many more parameters on a per-pixel basis.

Note

In Visual Pinball, materials don't include the texture. Instead, the texture is applied on a per-object basis.

Physics Materials

We refer to how the material interacts with the ball during the physics simulation as the physics material. It has these properties:

• Elasticity - The bounciness, how much the ball is thrown back when it collides.
• Elasticity Falloff - Pinball tables have a lot of rubber parts, and rubber has a special attribute: it gets less bouncy when hit at higher velocity. The falloff parameter controls how much.
• Friction - How much friction is applied when the ball rolls along this material.
• Scatter - Adds a random factor to the collision angle.

Physics materials are a way to group common behavior among certain objects, but contrarily to rendered materials, you can also not assign a physics material to an object and set each of those four parameters individually.

Note

In Visual Pinball, the physical parameters are part of the rendered material, so there is only one notion of material.

Conversion from Visual Pinball

As mentioned above, there are two differences between Visual Pinball and VPE how materials are handled:

1. VPE includes textures in the material, while Visual Pinball does not.
2. VPE differentiates between rendered and the physical material.

When importing a .vpx file, VPE converts the "visual part" of Visual Pinball materials into materials for the current render pipeline. It does that by creating a new material for every material/texture combination in Visual Pinball. The materials are then written to the Materials asset folder of the imported table where they can be easily edited and referenced. Since Visual Pinball uses different shaders than Unity, the results of the conversion are approximations and should be heavily tweaked.

Since VPE uses the same physics engine as Visual Pinball, the physical values of the materials don't need to be converted, they are copied 1:1 into a new physics material and saved in the asset folder.