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Advanced Rendering in Revit
Posted by Thang Le Toan on 21 August 2015 01:13 AM
By now the advantages of Building Information Modeling (BIM)—specifically the Autodesk® Revit® platform—over simple CAD programs has been extensively analyzed, examined, and proven. More efficient workflow, quicker results, higher profit margin, yada yada yada. I know this; you (should) know this; so let’s delve into a topic less often discussed: Presentations.
By presentations I don’t mean construction documents, which are yet another benefit Revit provides over CAD. I mean presentations like most of us did in college and few of us get to do anymore. Today, presentations are a task usually reserved for someone with a focus in graphic or interior design. I’m referring to presentations that contain images usually generated by a program few designers have mastered (such as Autodesk® 3ds Max®) and are often outsourced by firms that don’t have the personnel experienced with those programs.
Personally, as the project budget and time allows, I send my projects to Alex at Arccentric, based out of Chicago, Illinois, (http://www.arccentric.com/) for renderings or animations. I am sure your firm has a visualization expert on speed dial as well. But when I’m working with a tight budget and the client needs “something that looks nice,” then I take advantage of the under-used presentation features in Revit—shading, shadows, materials, rendering—to create the images best suited to represent my client’s project.
This article will show you how to create a multitude of presentation-quality images to satisfy the needs of the majority of your clients (regardless of how diverse they are), as well as add to your firm’s portfolio, all the while bypassing the costs associated with professional visualization experts.
Setting Up the View
If you have two eyes and are not a politician then the world you see most likely contains perspective. Therefore, you should be using the camera tool to create your presentation views. Using this tool is a simple two-step process. After selecting the camera ( ) in a plan view, click the mouse once to represent where you are standing relative to your building (your default eye height is 5’-6” from the level you are placing the camera), then click it again, somewhere in the direction of where you want to look.
That’s it! Revit will automatically create the perspective view following the second click of your mouse.
Figure 2: Perspective View in Hidden Line style.
Like most things in Revit, this newly created view is easily adjusted and manipulated. A great way to do this is by using the full navigation wheel, which is located within the view. I’ll admit I was not a fan of this for many versions of Revit, but I have grown to love it—especially the “Walk” and “Look” tools within it. Once you get the hang of the wheel, you’ll find it does a nice job of simulating your presence in the view and looking at exactly what you want to see.
One adjustment you should make now that becomes important later is the size of the view you just created. Since Revit is a vector-based program, the resolution will never deteriorate and will always look the same on your computer screen. But when the time comes to print or export this image, the image dimensions should be set to at least the size you want it to be on paper.
Remember, shrinking a large image affects its quality exponentially less than enlarging a small image. The lesson here: bigger is better. Adjust your image size by selecting the grips of the crop box to get the exact proportions you want. Then, to get the proper dimensions of that view, select the Size Crop button in the toolbar ribbon and input the specific dimensions you want. Be sure the “Scale” option is selected to maintain the proportions you just created.
Figure 3: Resizing the new Perspective View.
Once the perspective view is created, its default visual style is most likely Hidden Line. While this may look nice (especially to AutoCAD users or…gasp…Neanderthal hand drafters) we can do so much better.
Generate shadows using the Shadows On/Off button ( ) near the bottom left of your screen OR by opening the Graphic Display Options located in the properties dialog box of your view.
Figure 4: Controlling shadows with Graphic Display Options.
Shadows are easily controlled by adjusting the “Lighting” and “Sun and Shadow Intensity” settings in the Graphic Display Options. This allows you to create accurate shadows based on your building’s specific worldly location or to simply add shadows to express dimension, depth, and contrast to your building.
Figure 5: Perspective View in Hidden Line style with Shadows.
Color + Background + Ambient Shadows
For the next example I will focus on a Revit family within a project to demonstrate the power of color (named Shaded Views in Revit) and to show off my favorite, little-known Revit tool, Ambient Shadows.
Color complements the shadows we added earlier and creates even more “pop” to your images. All Revit objects can be assigned materials, so we can specify what they look like in Shaded View independent of their realistic material. The advantage to this is we can create a view which provides a good representation of objects (for example: wood is brown, brick is red, grass is green, and so on) without spending the extra time to set the true materials necessary for realistic or rendered views.
Adding a Gradient Background and Ambient Shadows are possible once again through the Graphic Display Options. Selecting the box to show Ambient Shadows gives your object or project even more of a realistic touch, while still saving you the time required to do a full rendering. While regular shadows are created from a singular light source in Revit, the Ambient Shadows tool creates shadows more realistic to the world we live in, which often has multiple indirect light sources.
Figure 6: Shaded View
Figure 7: Shaded View + Shadows
Figure 8: Shaded View + Ambient Shadows + Gradient Background
Gradient backgrounds provide a simulated surface or sky using three colors of your choosing. This is just one more option to create a more complete scene for your objects and projects.
One of the attributes of other modeling programs, such as Google Sketchup, that many people like is the ability to see real materials in their model without going through the rendering process. Recent releases of Revit Architecture have since added that ability.
Before getting an accurate Realistic Visual Style, we must first make sure the correct realistic materials have been set to the corresponding object materials. One disadvantage to this is that it can take a fair amount time to find and properly represent the correct material. Another disadvantage is that certain materials look better than others in the realistic view, so using those may dictate how you set up your camera as well as which materials you select. The big advantage, of course, is that you have a realistic looking view of the space you designed in less time than it takes to fully render.
A Realistic Visual Style view combined with shadows and ambient shadows generates a presentation quality image sure to satisfy even the most discerning client.
Figure 9: Realistic View + Shadows+ Ambient Shadows
The final presentation option offered in Revit is the ability to do a photorealistic rendering. This option is certainly the most time consuming, but also the most visually rewarding when done properly.
The quality of your image post-render is determined by the output and quality settings you choose. Personally, I choose to use “Printer Resolution” which renders an image to the exact size of the crop box we specified previously. This will create a higher quality image than choosing “Screen Resolution” and consequently a larger file size. In addition, you can choose six possible quality settings and you can also specify various DPI, which affects the quality and detail level even further.
Figure 10: Rendering resolution settings.
Many of the preparations for rendering, such as the proper set up of materials and lighting, have already been covered in this article. For exterior daytime renderings, use the Sun Setting options within the Rendering dialog. This allows you to create a precise sun angle and position relative to your building. Or, if you specified a real-world location, then just state the time and date and Revit will accurately portray the sunlight for that time, date, and location.
Figure 11: Specifying sun settings in the Rendering dialog.
Figure 12: Final rendering at best quality.
Once your settings are determined, the actual render time will vary based on your computer hardware and whether you are using a single computer or technology such as rendering farms or cloud computing. In this case, my desktop rendered the house in 62 minutes at best quality, while the same image took only 90 seconds using draft quality. As always, the bigger the image and higher quality the output, the longer it will take to render.
Image Editing and Exporting
Post-render image adjustment is often done in feature-packed image editing software such as Adobe Photoshop. But were you aware you can make an assortment of minor changes to your rendered image within the comfortable confines of Revit?
Figure 13: Post-render exposure adjustment settings.
The four skyscraper images in this article (Figure 14) were rendered using a night scene and a few artificial lights. The original rendering is on the left. The remaining three images were all generated by tweaking various elements of the exposure adjustment options within Revit.
Figure 14: Effects of exposure adjustment.
Once everything is to your liking, and more importantly, receives the approval of your client, it is time to export the image. If you rendered the image, first select the Save to Project button, which will add that rendering as a new view to your project browser. You can then choose to export the image as a JPG or other image file format. The other option for exporting is via the main File menu by choosing Export>Images and Animations>Image.
Figure 15: Image exportation settings.
You will see a dialog box that allows you to select the settings of your choosing for exporting. For good quality images to use in presentations, I recommend using the “zoom to” option, which will export your image to the exact dimensions you made the crop region around the view and setting the quality to 150 or 300 DPI. All non-rendered images in this article were exported in this manner.
Creating a Presentation
Now that we have all these high-quality, outstanding, presentation-worthy images, what are we going to do with them? Assuming we don’t know programs best suited for this task such as Adobe Photoshop or Illustrator and we are not well versed in Microsoft PowerPoint, why don’t we keep it in house? After all, we have done everything else in Revit, so why not create a presentation board within our Revit file? Great suggestion! Let me explain how.
Just as we produce construction documents using text and views within our project browser, we can create a custom title block to use as our presentation board template. Then it is just a matter of using our creative juices to combine text, project images, inspirational images, and other elements to create a polished, professional presentation.
Figure 16: Revit-created presentation board.
As you can see, you do not need to possess a degree in graphic design or be well versed in a plethora of design software to create good looking, client-pleasing, design-review-committee-satisfying presentation boards. By experimenting with the numerous presentation-oriented tools provided in Revit, you too can design and create high-quality images to add to a presentation board using the exact same program you use to generate construction documents, schedules, and everything else projects require.
Figure 17: Reflex Render Image (Courtesy of aAECs).
At the time this article was written, there were rumors of a new Revit add-on program named Reflex Render by Advanced AEC Solutions (aAECs) www.aaecs.com, being released in time for Autodesk University. This is said to revolutionize the design presentation process as we know it. If the previews I have seen are any indication of Reflex’s power, then it might just be the next big design software boom. It’s worth it to expand your software knowledge to add the ultimate rendering program.
Kyle Benedict (M. Arch.) is the founder of RADiCaL Design Solutions, a design studio which specializes in handicap accessibility design and consultation. He also established therevitcollection.com, an online assortment of modern Revit components. He resides in Atlanta, Georgia, USA, and can be reached at firstname.lastname@example.org
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