Rendering different types of grass has always been a challenge in architectural graphics, especially for the average designer who does not specialize in developing computer-generated imagery (CGI).
The best we could do in the past was to apply a bump map and maximize the setting, so the ground did not look completely flat.
Then, Enscape totally changed the game by automatically adding 3D grass within their real-time photorealistic rendering engine and giving us control over the height and height variation of the blades of grass. And now, they've gone one step further with the introduction of animated grass and vegetation (version 2.8 upwards).
Any material in Revit, SketchUp, Rhino, Vectorworks, or Archicad with the word “grass” in its name will render, by default, as a thick three-dimensional-looking grass in Enscape. Even in the small comparison images below, it is easy to see what a big difference there is.
This article will cover the ins and outs of the 3D grass rendering feature in Enscape, with a focus on Revit and SketchUp.
Revit’s flat Grass material
Enscape’s 3D Grass feature
Detailed view of Enscape’s 3D grass feature
Here are a couple of images I have created which greatly benefit from a realistic and natural-looking grass pattern. Each grass image was rendered with Enscape and has had no post-production edits.
Grass shown in a transportation project
3D grass shown in a landscape architecture project
What’s more, animated grass looks amazing in real-time presentations and videos. Take a look at this short video clip with beautiful 3D grass.
Rendering 3D grass in Revit
Using Autodesk Revit, we can achieve amazing results in Enscape by employing various materials to define grass types. Let’s look at how this works and what the options are.
Grass height
The magic happens when Grass/Carpet Rendering is ticked within the Enscape General Settings dialog and one or more Revit materials have the keywords “grass”, “short grass”, “tall grass” or “wild grass”.
Tip: The images in this post are enhanced with Enscape assets such as people, trees, shrubs, dandelions, a basketball, and a vehicle. These components are included at no extra cost with Enscape.
Here is an example of the different grass types compared side-by-side.
Revit material with keyword ‘grass’ in the name
Revit material with keyword ‘short grass’ in the name
Revit material with keyword ‘tall grass’ in the name
Revit material with keyword ‘wild grass’ in the name
Here is what happens based on keywords used in the material name:
- Grass: Medium grass
- Short Grass: Shorter grass
- Tall Grass: Taller grass
- Wild Grass: Taller grass with varying blade heights
TIP: The keywords are not case sensitive, but you cannot change the order, e.g. “grass tall” is not the same as “tall grass” to Enscape.
Grass color
Because Enscape samples the color or texture assigned to the material, we can achieve interesting results. I have been using this texture for a while as it has subtle variations in color, which translates nicely to Enscape’s 3D grass. It was acquired from a larger high-resolution aerial image.
Texture I often use for the grass material texture
As shown in the following image, I set the texture size to 120’ square; thus, the patterning within the grass image is not obvious in Enscape due to the scale. Feel free to right-click and save this texture and give it a try in your project.
Here are the results in Enscape. Notice that the color is not consistent, which produces an effect that often occurs due to droughts. So, the result is a more natural grass pattern if this is the look you are going for.
Grass rendered using texture shown above
Detailed view of grass rendered using 3D texture shown above
Grass types
Now let’s look at how we can create specific, real-world, grass types. You will be happy to know it is easy with Enscape.
First, let's test a few grass types shown in the image above: Centipede, Bermuda, St. Augustine and Zoysia.
I found this image by searching the internet for “grass types”. I then cropped the image down to just the desired grass type (no text or lines) and saved a separate image, with a texture size of about 8-12” (20cm – 30cm) wide and 4-5” (10cm – 13cm) tall. Each grass image produced one of the results shown below. Of course, finding larger tileable samples would produce better-looking results and look more accurate in Revit if ‘realistic view’ were ever used.
Here are the results of my ‘grass types’ study in Enscape:
3D grass: Centipede3D grass: Bermuda
3D grass: St. Augustine
3D grass: Zoysia
Tip: Grass is not intended to be applied to predominately vertical surfaces, as the blades of grass are generally vertical, not perpendicular to the surface.
Out of curiosity, let’s look at what the two default Revit grass materials look like in Enscape – these are the ones that install with the software. There is a big difference. The one actually called “grass” is way too dark. The other is better, but still a little off. And this will change with the lighting, so remember to consider the albedo; setting the real-world base color of a material results in more photorealistic graphics in various lighting conditions.
Revit’s default grass material
Revit’s default 'plant' material
With this, we can see the variety of options we have to represent grass types in Revit. Some of the techniques offered in the next section on SketchUp can also be applied in Revit. However, Revit does not have the detailed sliders for height and height variation.
TIP: If the grass is poking through your floor or walk in Revit, add a Building Pad below the floor/walk to stamp out the top of the toposurface in that area.
Rendering 3D grass in SketchUp
When rendering in SketchUp, we have all of the options just covered for Revit, and a few more!
In fact, because of the Enscape-centric Material Editor and ability to place custom proxy objects, some designers will export their Revit model to SketchUp to finish the rendering task there.
For my SketchUp examples, I downloaded the model Walled Garden with Rock Waterfall created by JBJDesigns.
Notice in the Enscape Materials dialog the Type is set to Grass and we have two sliders near the bottom; one for Height and another for Height Variation.
You can quickly set your selected SketchUp material type to grass via the dropdown menu. The grass settings are only visible if the type is set to grass. Use the Height slider to adjust how long your grass is. The Height Variation slider adds variation to the height and size of the grass blades. The higher the amount of height variation, the wilder your grass will look. If you would prefer a more uniform appearance, set the slider to a low value.
When setting the material via keyword, the type is automatically set to grass because the SketchUp material name has the word ”grass” in it. But, we can also manually change the name if needed. In this model, there were a few materials with the words “vegetation” and “grass” in the same name. Those materials default to Vegetation so I must either change the name or manually change the type… I did the latter.
Grass height (0,50,100) and variation set to zero
Sports fields
If you are designing a sports field or stadium, you will be happy to know Enscape can produce extraordinary results for this application! I did a quick search, again on 3D Warehouse, and found a high-quality model of the Gillette-Stadium created by Cleveland Rocks to explore this use case.
In this SketchUp model, each grass color is a different material. All I did for each of these materials was to make sure the type was set to grass and adjust the height and variation sliders to zero. And that was it! Just five minutes into opening this model and I was able to navigate a photorealistic rendering in real time, even adjusting the time of day.
Various grass materials used to define a sports field
Here is a detailed view of the logo defined by several different grass colors.
Detailed view of logo defined with grass material
The high-quality 3D grass created by Enscape looks amazing when the camera is in motion as well. Check out this lively high-resolution video I created of this scene:
Animated grass
Finally, with Enscape 2.8 and above, animated grass and vegetation is available to help make our scenes and landscape renderings even more realistic. It's possible to control the wind strength and direction to bring our landscaping scenes to life in our walkthroughs, videos, and even in virtual reality.
Conclusion
It’s truly exciting to see such dramatic results for 3D grass in a real-time rendering engine, which also has a live link to our favorite 3D modeling environments. And if you think the grass is amazing in these still images, wait until you see it in virtual reality using the Oculus Rift, HTC Vive or Windows Mixed Reality devices. It is breathtaking and very memorable for clients and stakeholders.
For more inspiration, be sure to check out the Enscape Visualization Gallery to see what other customers are doing. If you have yet to give Enscape a try, download the free trial today and check it out with Revit, SketchUp, Rhino, Vectorworks, or Archicad. If you are a student, be sure to take advantage of the student version.
