Overview
In this lesson, students explore how to use Autodesk Revit to adjust the appearance of the building model elements that appear in their 2D and 3D views. They will learn how to:
- Assign materials to model elements through object styles, type properties, and instance properties.
- Adjust the render appearance of materials to display realistic views.
- Render views to create realistic views in daylight and artificial lighting conditions.
Assigning Materials to Model Elements
You can assign materials to the elements in a building model to accurately display their appearance in shaded and rendered views. All elements in a building model have a material—either a default material based on the object category or a specific material that has been assigned through the element’s type or instance properties. Materials are assigned to elements using this hierarchy:
- Defaults—using default materials, which typically display a solid gray color.
- Object style—using the materials assigned to an object category or subcategory.
- Type properties—using the materials assigned to all elements of the same type in the family’s type properties.
- Instance properties—using the materials assigned to a single element through its instance properties.
If an element has properties that assign a material at a higher level in this hierarchy, lower-level settings will be overridden. For example, a furniture element that has materials assigned through its type properties will use those materials, rather than the default material assigned to the furniture category.
Changing Material Display and Render Appearance
Revit software includes an extensive library of predefined materials and rendering appearances, and you can edit the existing materials or duplicate them to create new ones as needed for your design.
Use the Material tool in the Manage tab to edit existing materials, create new ones, and specify how the materials will be displayed in views. You can set these options for hidden line, shaded, and consistent color views:
- Shading color
- Transparency
- Surface patterns (for cut and uncut surfaces)
You can also assign a render appearance to each of the materials that will be displayed:
- Views set to use the realistic visual style.
- Photorealistic views created using Revit software’s rendering tools (which we will learn about in the next lesson).
To change a material’s render appearance, open the Materials dialog box, then switch to the Render Appearance tab, where you can browse the library of render appearances by material type or search to find specific items. You can:
- Replace the current render appearance by choosing a new one from the library.
- Adjust the settings to change or fine-tune the current render appearance.
Creating Exterior Rendered Views
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Autodesk Revit software can render photorealistic views that accurately portray the materials selected as well as the effect of lighting and shadows. Rendered views are useful for presenting your design to clients and other reviewers who want to preview the appearance of the finished building.
Figure 1.7.1. - Shaded and rendered images of the same view
You can render any 3D orthogonal or perspective view to create a photorealistic image.
Open the Rendering dialog box by clicking the Show Rendering Dialog button in the View Control Bar, where you can specify these settings:
- Quality—the overall quality of the rendered image, ranging from Draft to Presentation quality. Higher-quality images are more realistic, but take much longer to produce.
- Output resolution—the number of dots per inch (DPI) to produce in the rendered image. Higher-resolution images are useful when they will be blown up or printed at high quality, but also take longer to produce because more data is computed.
- Lighting scheme—the sources of light that will provide illumination. For exterior renderings, the sun is typically the primary light source.
- Background—the appearance of the sky. If you prefer, you can specify a background image rather than using Revit software’s automatically generated sky.
The rendering settings chosen has a very dramatic effect on the amount of time required to render a view. For this reason, it is typically wise to:
- Start by testing your renderings at draft quality to see the results quickly.
- Use these draft renderings to identify any elements that need to be adjusted or corrected (for example, materials that are not assigned properly).
- Create another rendering at draft or low quality to confirm the adjustments. You can limit the region rendered to focus on the area where these elements appear, rather than rendering the entire view.
- When all the changes are confirmed and you are confident about the rendering results, create a final rendering using medium, high, or presentation quality.
Creating Interior and Nighttime Rendered Views
You can also create photorealistic renderings of interior 3D views to see materials selected and explore lighting effects. Interior views can be rendered to show the effect of daylight transmitted through openings, windows, and curtain walls. But, depending on the sun’s position and time of day, you will often need to supplement the sunlight with artificial light sources (for example, lamps, surface fixtures, and recessed lights).
You can use artificial lights to:
- Explore the effects of using different lighting schemes and fixtures to illuminate a space.
- Create evening or nighttime renderings that will be lit primarily through artificial lighting.
To use artificial lighting, place lighting fixture components in your building model. Then use the artificial lighting controls in the Rendering dialog box to specify the light settings used in each view.
Renderings that use artificial lights can take a long time to run (up to several hours, depending on your computer’s hardware and the rendering settings chosen) because the effects of the light produced by each fixture that is turned on must be calculated. When using artificial lights, choose your rendering settings very carefully:
- Use draft renderings to get quick results and identify any problematic elements.
- Limit the region rendered to focus on specific areas as you test the effect of lighting settings.
- Turn off any lighting fixtures that are not needed to provide light for this view.
- Adjust the exposure settings to control the overall brightness of the image and the highlights and shadows.
- Reserve the higher-quality settings for final renderings, when you are confident about the expected results.
Learning Objectives
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After completing this lesson, you will be able to:
- Explore the visual effect of specifying various materials for different building elements.
- Appreciate the importance of providing adequate daylighting and artificial lighting sources in a building.
- Accurately present views of buildings models in realistic and effective ways.
Tutorials
Assigning Materials to a Component
In this exercise, you will learn how to:
- Assign materials to model elements by object category.
- Assign materials by altering an element’s type properties.
- Assign materials by specifying an element’s instance properties.
Figure 1.7.2. Assigning materials in the Object Styles dialog box
Video Tutorial
Student Exercise
- Create a new floor type using a different material and thickness for the deck at the east side of the residence and studio and the ramp coming from the driveway:
- Open the Exterior Perspective view and note the appearance of the deck. A cast-in-place concrete material has been assigned to this element, and it is displayed with gray shading and speckled pattern.
- In a plan view, select the deck and create a new type called Wood Patio, then edit the structure for this new type:
- Change the thickness of the Structure [1] layer to 4" (0.10 meters).
- Change the material assigned to this layer to Wood Deck.
- Also assign this material to the ramp from the deck to the parking area.
- Next, change the materials assigned to the Console Table in the living room of the residence to match the other furniture in the room:
- Select the sectional sofa component, and determine the materials assigned to the various parts.
- Select the console table and assign similar or complementary materials to its parts. The materials for this component are specified as instance properties, so every instance of the console table can have different materials.
Figure 1.7.3 - Exterior perspective view showing new wood material assigned to the deck and ramp
Creating New Materials
In this exercise, you will learn how to:
- Create new materials by duplicating existing ones and setting the shading color and surface pattern.
- Replace the render appearance assigned to materials using options available in the Autodesk library.
- Adjust settings to fine-tune or alter a material’s render appearance.
Figure 1.7.4. Choosing a material’s render appearance
Video Tutorial
Student Exercise
- Create the following new materials to be assigned to the Eames chair in the living room of the residence, and choose an appropriate render appearance for realistic and rendered views:
- Eames Chair Frame―use Teak from the wood library and change the surface pattern to Wood 3.
- Eames Chair Leather―use Creased Black from the leather library.
- Eames Chair Metal―use Chrome Polished from the metal library.
- Assign these new materials to the Eames Chair component:
- Seat fabric―use Eames Chair Leather
- Metal parts―use Eames Chair Metal
- Wooden shell―use Eames Chair Frame
- Open the Living Room Interior view and choose the realistic visual style to see the new render appearances applied to the elements.
Figure 1.7.5 Living room view using realistic visual style to show render appearance of materials selected
Exterior Renderings
In this exercise, students will learn how to:
- Choose the rendering quality and set the output resolution.
- Limit the region rendered.
- Specify sun settings to set the lighting level and cast accurate shadows.
- Edit background properties for a view to choose how the sky will be rendered.
- Fine-tune the exposure settings of a rendered image.
Figure 1.7.6. Choosing rendering settings
Video Tutorial
Student Exercise
- Using an exterior perspective view, create an exterior rendering of the residence and studio displaying accurate shadows and using Draft quality to reduce the time required:
- Choose the Exterior: Sun only lighting scheme for this daytime rendering.
- Adjust the sun setting options:
- Choose the Still option for the solar study.
- Set the location to the city near where you were born.
- Set the date to your birthday and the time to 10:00 AM.
- Run the rendering and save the results to the project as Exterior Perspective Draft
Figure 1.7.7 - Exterior rendering at draft quality
- Create another version of this rendering using Medium quality and keeping the other settings the same:
- When the rendering is complete, fine-tune the exposure settings by opening the Adjust Exposure dialog box:
- Raise or lower the Exposure Value slightly to brighten or darken the entire image.
- Adjust the highlights to darken or brighten the brightest portions of the image.
- Adjust the shadows to lighten or darken the darkest portions of the image.
- Experiment with the other settings to explore their effect on the image.
- Save this rendering to the project and name it Exterior Perspective Medium.
Figure 1.7.8 - Exterior rendering at medium quality
Interior Renderings
In this exercise, you will learn how to:
- Set the lighting scheme to include artificial light sources
- Turn on light fixtures and adjust the dimming level
- Create light groups
Figure 1.7.9. Setting artificial light sources
Video Tutorial
Student Exercise
- Using the Living Room Interior perspective view, create a draft nighttime interior rendering of the living room area using artificial lighting sources to illuminate the view:
- Choose the Interior: Artificial only lighting scheme for this nighttime rendering. (The sun settings will be ignored).
- Click Artificial Lights to open artificial lights settings for this view.
- Turn on the checkbox next to all of the lighting groups except the Studio Lights. You can also select any individual light, then turn it on or off or set its dimming level.
- When the rendering is complete, click Adjust Exposure to adjust the exposure settings.
- Raise or lower the Exposure Value slightly to brighten or darken the entire image.
- Continue tuning the exposure value to create a good compromise between brightness and overexposure.
- Save the rendering to the project and name it Living Room Interior Draft.
Figure 1.7.10 - Interior renderings at draft quality (showing default and adjusted exposure settings)
- Create another rendered view using the medium quality setting to improve the rendering of the shadows and lighting effects:
- Adjust the artificial lighting settings to dim some of the lighting fixtures:
- Set the dimming level for the floor lamps to 0.7 (70%).
- Set the dimming level for the ceiling lights in the seating area to 0.8 (80%).
- Fine-tune exposure settings of the completed rendering:
- Find an exposure value that creates a pleasing overall level of brightness.
- Adjust the highlights to darken or brighten the brightest portions of the image.
- Adjust the shadows to lighten or darken the darkest portions of the image.
- Save this rendering to the project and name it Living Room Interior Medium.
Figure 1.7.11 - Interior renderings at medium quality (showing default and adjusted exposure settings)
Assessment
Assigning Materials to Model Elements
- If you cannot find material settings in an element’s type or instance properties, how can you assign materials to the object?
Changing an element’s type or instance properties are high-level ways to edit materials assigned to the object. If these options are not available, the object style for the category that the element belongs to can be changed. For example, if a door is displayed as gray and material options are not available in its type or instance properties, you can change the object styles for the Door category in order to set a default material for all door components.
- What are the advantages and disadvantages of assigning materials as type properties versus instance properties?
Instance properties allow for an easier way to create variability between multiple instances of the same component. If we have multiple objects that we would like to be different materials, instance properties allow us to change each one individually. However, if we want to change the material of many instances at the same time (like a large set of chairs), assigning materials as a type property is much easier.
- If you want to define a new material for some elements in you model, is it better to change an existing material or to duplicate one and change the settings of the new material?
It is typically better to duplicate a similar material when creating a new one. This prevents you from deleting a useful material or accidentally changing a material that is being used elsewhere in the project.
Changing Material Display and Render Appearance
- If you want to change the render appearance of some of the elements in your model, is it better to modify an existing material’s settings or to create a new material and assign it to those elements?
If you are sure that you want to change the render appearance of every element using a specific material, then it is generally okay to modify the render appearance of that existing material. Otherwise, create a new material for each element that needs to be altered.
- When creating new render appearances from photographs or scanned images of materials, what types of images work best?
Pictures and images with repeated patterns and limited distortions caused by a poor camera angle work best for creating new render appearances.
Creating Exterior Rendered Views
- How is the time required to render an image affected by the quality setting and output resolution?
Changing to a higher-quality rendering setting or raising the output resolution increases the time required to render a view.
- How are the shadows cast affected by the location specified? By the date and time?
Any variable that affects the sun’s location will have an effect on the shadows that are being displayed. If the sun is high in the sky, due to geographical location or an afternoon time setting, the shadows will be short and close to the structure. If the sun is low in the sky, the shadows will be very long.
- If a completed rendering appears dark, is it better to rerun the rendering with different lighting settings or adjust the exposure of the existing image?
The fastest way to fix the darkness of an image is to adjust the exposure settings, so this method should be attempted first. If this does not produce the desired effect, the view can be rerendered using different lighting and sun settings. To save time, test render a portion of the image using the region box to see the effect of the setting changes.
Creating Interior and Nighttime Rendered Views
- Why do renderings that include artificial light sources take so much longer to produce?
The rendering engine must consider and calculate the effects of the light being cast by each light source. Exterior rendering typically consider a single light source—the sun. Interior renderings often include many light sources to illuminate the view, so the calculations and time required are multiplied many times.
- How would you set up the lighting scheme for a later afternoon view to include the effect of sunlighting through the curtain wall as well some artificial lights?
By using the scheme Interior: Sun and Artificial, both the sun and artificial lights will be considered in the rendering. This also makes the Artificial Lights dialog box available.
- What are the advantages of placing light fixtures in light groups? Are there any disadvantages?
There are typically no disadvantages to placing light fixtures in groups. Lights that have been grouped can be turned on, turned off, or dimmed simultaneously or controlled individually if desired.
Key Terms
Key Term | Definition |
Rendering | The process of creating realistic images of a model by replacing the shaded appearances of materials assigned to the visible elements with images of actual materials. |
Model Category | A grouping that includes similar model elements. For example, tables, chairs, and beds are all members of the Furniture model category. Materials can be changed by editing an object category’s style. |
Object Style | Settings that determine how elements that belong to a model category are displayed if the materials are not assigned through the element’s type or instance properties. |
Lighting Scheme | A setting that specifies the sources of light that should be considered when rendering a view. |