Import CAD Materials

When 3D Models are imported, their assigned materials are imported as well. Materials can be accessed in 2 areas:
1. The imported “materials folder” within Generated Scenario Assets in the Asset Library Window.

2. By selecting a part/object and using the “Object Properties” window.

Note: All imported materials are converted to a “Standard Material”. Material creation and adjustments are covered in detail later in “Working with Models/Model Refinement”.

 

Create Materials

Select a part/object and using the “Object Properties” window, go to Material>Create New Material.

 

Material Properties

1. Diffuse Color: This refers to the base color of the material. In PBR, it represents the color of the surface under neutral lighting conditions. It influences how the material absorbs and scatters light.
   The "Diffuse" material type is a shader that only uses this property.

2. Diffuse Map: A texture map that provides detailed color information for the material's surface. It's used to add realism by including details like patterns, gradients, and variations in color.
   An example of a diffuse map for a brick wall:
   

3. Alpha Mode:

   • Opaque: The material is fully opaque, and no light passes through.
   • Blend: This mode allows for transparency in the material, where the level of transparency can vary across the surface.

     • Alpha: Ranges from 0 to 1, 0 being fully transparent, and 1 being fully opaque.

       Tip: While Using blend in combination with an alpha of 1 results in a visual approximation of an opaque material, we recommend setting the material type to Opaque in that case. Unless you're actually using a texture that contains transparent information, like a png with transparent pixels. Since blend mode puts objects on the transparent render queue, that means they get occluded by other objects based how far away their pivot is from the camera, which may result in undesired results. Opaque is also a bit less expensive on the GPU. This might be an answer to when you have a question like "Why can't I see my object while it is not actually hidden?".

   • Mask: This mode uses a threshold value to make parts of the texture either completely opaque or completely transparent, often used for materials like foliage.

4. Normal Map: A texture that adds detail to the surface without changing its geometry. It simulates small-scale bumps and dents by altering the way light interacts with the surface.
   For example, a normal map for a brick wall could look like this:
   

5. Metallic Roughness Map:

   Combined Metallic-Roughness Map

   1. Texture Channels:

      1. The Metallic Map is stored in the blue channel, it controls metalness.

      2. The Roughness Map in the green channel of the texture.

      3. The red and alpha channels are not used

         

   2. Appearance: When combined, the texture might look unusual with different shades of blue and green. Each color channel encodes different information (metallicity and roughness).

      This combined approach reduces the number of textures needed, which can enhance performance. The use of this map allows for more realistic and physically accurate rendering of materials, as it closely mimics how light interacts with different surfaces in the real world.

6. Metalness: This property determines how metallic the material is. A high value makes the material behave like metal, with increased reflectivity and specific color influences in reflections.

7. Roughness: Controls the microsurface details of the material. A low roughness value results in a smooth, reflective surface, while a high value leads to a more diffused, less reflective surface.

8. Emissive Color: This is the color of the light the material emits. It makes the surface appear as if it's giving off light, which can be used for things like screens, signs, or magical effects.
   The "Diffuse Unlit" material type is a shader that only uses this property.

9. Emissive Map: A texture map that dictates which parts of the material emit light and in what color. It allows for detailed control over the emissive properties of the material.

10. AO Map (Ambient Occlusion Map): This map provides information on how exposed each part of the surface is to ambient lighting. It helps to add depth and realism by darkening creases, holes, and surfaces that are close to each other.
    An example of an AO map for a brick wall.
    

Special Material Presets

The easiest way to change a material preset, is to select an object that has a material applied to it, and observe its properties in the Object Properties window. Alternatively, you can also select a material in the Asset Library under the Generated Project Assets section, to observe its properties. Under Material > Material Preset, you can find a dropdown with all 5 material preset types:

• diffuseUnlit: a material preset that does not receive influence from light, it behaves like an emissive material.
• standard: the default material preset, exposing most common material properties.
• depthMask: a material that will make objects function as occlusion masks.
• video: a material preset that allows you to map an mp4 file to an object.
• line: a material preset that renders lines of an object, by offsetting its edges.

depthMask Material

The depth mask material will use an object that uses this material as an occlusion mask for other objects behind it.

This material doesn't render a visible surface in the traditional sense but instead influences what parts of the scene are visible or hidden based on depth.

Key characteristics of a Depth Mask Material include:

1. Masking Effect: The depth mask material can act as a 'mask' that hides or reveals parts of other objects behind it based on their depth. It's like a stencil that cuts through the scene, showing only what's beyond a certain depth.

2. No Visual Appearance: Unlike standard materials, a depth mask material usually does not have a diffuse color, texture, or other visual properties. Its primary function is to affect the visibility of other objects in the scene rather than to be rendered itself.

3. Use in Special Effects: It's commonly used in visual effects, such as creating the illusion of objects moving in and out of surfaces, or in scenarios where the interaction of objects at different depths needs to be controlled precisely.

In essence, a depth mask material is a tool for managing the complexity of rendering scenes where the relative depth of objects affects their visibility or the visual effects applied to them.

 

Video Material

Default material that is generated when dragging an mp4 into the scene.

It essentially loads the video in the emissive map channel, the color should generally be set to white #ffffff, in order to enjoy the colors of the original video.

 

Line Material

The line material is a specialized shader.

It technically renders an offset in the normal direction of each surface of the object it's assigned to (distance is controlled by the Line Thickness parameter). After that this new offset surface is masked with its original surface, generating the illusion of a line. As a result, internally, the geometry set is duplicated, as a performance impact could be expected when using this shader on high triangle count objects, we recommend to use it on smaller, lower triangle count objects.

1. Line color: the color of the lines generated.
2. Line thickness: an indication of the thickness of the lines generated.

Tip: a great visual effect can be achieved by duplicating a parent object, and then assigning:

1. A depthMask material to one instance
2. A line material to the other instance

This will create a visually pleasing outline of the visible edges of a model.