Preparing a Scene for Advanced Rendering

Set up two identical scenes to compare the effects of advanced rendering.

Rendering a photorealistic scene requires the use of several materials to represent the different components on the model. Every material has its own unique material properties. To capture these properties in Simcenter STAR-CCM+, you require a separate displayer for each material that you want to model. An overview of the materials used on the car is shown below. Parts that are contained in the same displayer (same color in the diagram) are rendered using the same material properties. You can set specific attributes and properties for each material.



Index Description Material Appearance
1 Car Body White (Gloss)
2 Plastic Trim Black (Gloss)
3 Simulation Data (Windscreen, Side Windows, Wing Mirrors) Static Pressure Field Function
4 Wheels Silver (Metal)
5 Tires Dark Rubber
6 Brake Rotors Gray (Matte)
7 Headlamp Lens Gray (Transparent)
8 Chrome Trim Silver (Metal)
9 Underbody and Air Intakes Black (Matte)

Open the provided scene and set it up for advanced rendering:

  1. Open the Scenes > Advanced Rendering On scene.
    The scene starts to render. The estimate time to completion is displayed on the top-right corner of the scene. If you are planning on making a lot of changes to the scene, and advanced rendering is turned on, the scene would update and render every time after each change. You can either choose to deactivate advanced rendering or reduce the quality of the rendering.
  2. Click the Scene/Plot tab.
  3. Select Attributes > Advanced Rendering Properties and set Quality to 0.1.
  4. Expand the Attributes > Lights node and set the Intensity property of Light 1 and Light 2 to 0.7.
  5. Change the color map of the scalars and streamlines:
    1. Expand the Static Pressure Windows, Streamlines: Wing Mirror, and Streamlines: Underbody displayer nodes.
    2. Multi-select the Color Bar sub-nodes of the displayers.
    3. Set Color Map to blue-red balanced.
  6. Create a displayer to contain the ground:
    1. Right-click the Advanced Rendering On node and select New Displayer > Surface.
    2. Rename the new displayer, Surface 1, to Ground.
    3. Select the Ground > Parts node and set Parts to Parts > Domain Box > Surfaces > Ground.
      Where possible, use the original geometry representation for parts instead of the wrapped/remeshed representation. The original geometry tessellation provides a cleaner look and does not include the small imperfections that can appear when you wrap the geometry. This option is particularly useful for complex shapes such as the car body. In cases where you want to show simulation data, such as the rotating wheels, or the static pressure on a particular surface, you must use the volume mesh representation (or the simulation history representation if you stored this data in a .simh file).
    4. Select the Ground node and set Representation to Geometry.
      This option uses the original geometry tessellation for this part.
    5. Set Transform to Car Body Wrap.Block.Symmetry 1.
      This option mirrors the ground into the symmetry plane.
  7. Define the color properties for the ground:
    1. Select the Ground node.
    2. Set Color Mode to Constant.
    3. Select the Ground > Color node and click (Custom Editor) next to the color.
    4. In the Color dialog, select the HSV tab and specify the following:
      Property Setting
      Hue 0
      Saturation 0
      Value 80
  8. Set up the advanced rendering properties for the ground:
    1. Select the Ground > Advanced Rendering Effects > Advanced Rendering Materials > Non-Physical node.
    2. Set Absorption to 0.8.
      Absorption specifies how much light is absorbed by the material and does not reflect or refract. The range is 0 to 1. A value of 0 absorbs all the light, making the material look dark.
    3. Set Reflection to 0.3.
      Reflection specifies how much of the light bounces off the material. The range is 0 to 1. A value of 0 makes the material have a matte appearance, and a value of 1 makes the material reflect all the light. The ground now reflects the objects that lie on top of it.

    4. Retain Refraction as 0.0.
      Refraction influences the amount by which light changes its direction as it passes through a material with a different optical density (index of refraction). A value of 0 does not change the direction of the light.
    5. Retain Index of Refraction as 1.33.
      The index of refraction influences how much the light changes direction when entering different materials.
    6. Select the Ground > Advanced Rendering Effects node and activate the Enable Shadows option.
      This option enables shadows to be cast on the ground surface. The shadows from the car are cast onto the ground. You can control which surfaces receive shadows locally for each individual displayer, or you can control the shadows at a global level from the Advanced Rendering Properties node at the bottom of the object tree for the scene.

  9. Define the material for the tires:
    1. Select the Advanced Rendering On > Tires node and set Color Mode to Preset Material.
      This option allows you to use one of the preset materials listed under the Tools > Rendering Materials node. The render settings of these materials are predefined.
    2. Select the Tires > Preset Material node and set Material to Matte > Matte Dark Gray.
  10. Display the remaining simulation data in the scene:
    1. In the Advanced Rendering On node, multi-select the Streamlines: Underbody and Streamlines: Wing Mirror nodes, right-click and choose Toggle Visibility.
      The displayers are activated and the simulation data is loaded into the scene. The streamlines can take a few minutes to calculate before they appear in the scene.

    2. Select the Streamlines: Underbody > Scalar Field node and set Min to 10.
    3. In the Streamlines: Underbody > Advanced Rendering Effects > Advanced Rendering Materials node, set the Effect property to Metallic.
    4. Select the Streamlines: Underbody > Advanced Rendering Effects node and activate the Casts Effects option.

      This option causes the parts in the specified displayer to cast their effects onto other materials.

      In the following example, the view is zoomed into the front wheel to see the effects that the streamlines have on the other materials in the scene. With Casts Effects deactivated, the streamlines have no effect on the other materials in the scene.

      Activating the Casts Effects option causes the streamlines to appear in the reflection on the wheels, the car body, and the ground.

    5. Deactivate the Casts Effects option.
  11. Now that the scene is set up fully, select Attributes > Advanced Rendering Properties and set Quality to 0.25.
  12. Save the simulation.