Understanding Autodesk Revit Materials | Cadalyst

12 Oct

Starting with Revit 2013, there is a new term that users must become familiar with: assets. To better understand assets, let\’s first talk about the overall concept of a material in Revit 2014. Consider the simple illustration at right: This box represents the primary components of a material in Revit.

Think of a material as a container. Some of the information represents elements you can touch and see when the building is complete, while some does not. Assets are modules, if you will, that better define a material. These modules are optional and can be added or deleted as needed; however, most materials have an appearance asset, which cannot be deleted.

via Understanding Autodesk Revit Materials | Cadalyst.

Duplicating a Material and Its Assets

It is important to know how to properly duplicate a material in your model so you do not unintentionally affect another material. The process has changed significantly from previous years. Many experienced Revit users still do not fully understand this process. Not following these steps results in multiple materials being changed when only one material was intended to be modified. If you duplicate a material in your model, the appearance asset will be associated to the new material and the material you copied it from!

In this example, we will right-click on Carpet (1) and duplicate it. Before we duplicate it, notice the appearance asset named Red is not shared (see arrow No. 3).

Once you have duplicated a material, the two carpet materials in this example now indicate they both share the same appearance asset. Changing the new material will affect the original material. Click the Duplicate This Asset icon in the upper right.

Note: Another option, rather than duplicating the asset, is to import an asset from the library. Later in this article you will see an example of this which shows a chain-link fence asset being loaded into a material.

Finally, when the appearance asset has been duplicated, you can expand the information section and rename the asset. You can now make changes to this material without affecting other materials.

This applies to all assets in a material

Material Transparencies

Materials are only transparent in 3D views! The following images will explain this further and present you with a couple of options.

In any elevation view, materials are not transparent, as you can see in the left-hand image below (regardless of what Visual Style is set to). Even turning off the glass material in a view’s Visibility Graphics Overrides (VG) will not allow you to see through the “opening,” as seen in the second image. The trick here is to edit the opening in the family so it is transparent in elevation, as shown in the third image.

To achieve that, simply select the opening and check Elevation on the Options toolbar.

Once the opening is set to be transparent in elevation and the glass sub-category is turned off, you can see though the windows, as shown in the image below. – 

Once the opening is set to be transparent in elevation and the glass sub-category is turned off, you can see though the windows, as shown in the image below.

Another option is to adjust a 3D view to “front.” This is a flat view, just like an elevation, but is still technically still a 3D view. You can lock the view and add dimensions, tags, and notes. But you will not get grids and levels. Turn on the Section Box and you will even get the toposurface in section.

An image file can also be used to define a transparency in a render appearance asset, as shown in the image below. The lighter areas of the image are more transparent than the darker areas.

Fill Patterns

A definition from the Revit.PAT file:

Model vs. Drafting Patterns

There are two types of fill patterns in Revit: model and drafting. Model patterns are used to depict real-world elements, such as bricks, shingles, tiles, etc. They are defined and display in model units. An 8×16 inch brick pattern will show exactly 12 courses on an 8-foot-tall wall. A 2-meter-tall wall with a 200×400 mm brick pattern will have 10 courses. Model patterns appear denser at coarser view scales and sparser at finer ones.

Drafting patterns are defined in paper units. If you import the pattern at scale 1 and print at 100% zoom, the pattern’s dimensions on paper will be exactly as specified in the file, regardless of view scale. Drafting patterns are used to symbolically denote materials such as steel, concrete, sand, etc.

Drafting patterns are typically defined with smaller numbers than model patterns. Drafting patterns usually contain sizes from 0.04 to 1 inch (1–25 mm); model patterns usually contain sizes from 2 to 20 inches (50–500 mm). These are guidelines only, not enforced by Revit. Revit’s existing restrictions limit the maximum size and density of the patterns, and a review of these restrictions is planned for a future release.

Fill patterns are used to represent surfaces on a material. Any AutoCAD hatch pattern can be used by Revit. If you want an AutoCAD pattern to be used as a Model filled region (versus Drafting, which changes scale with the View Scale) you have to add ;%TYPE=MODEL to the PAT file, as shown below. The semicolon symbol (;) at the front will rem out the line so even AutoCAD could still use the file; however, it might be best to copy the ACAD.PAT file to another location specifically for Revit use.

You may also see some patterns with ;%TYPE=DRAFTING, as shown below, but Revit will assume drafting if nothing is specified.

When creating a model pattern, if you try to use the AutoCAD ACAD.PAT file without making any changes, you will get this error: “No ‘Model’ type patterns found.”

There are tons of patch patterns for AutoCAD one can find via the web. If you need something custom you can either edit the PAT text file, or use something like Hatch22. You just draw the hatch pattern you want in Revit, then use this add-in to automatically generate the PAT file. This file can then be imported back into Revit.

Using Revit’s Artificial Materials

Revit has several built-in features to make what I like to call artificial (or synthetic) materials, including tile, concrete, metal, and more.

Material tile pattern used in ceiling application.

Notice, in the image below, when the material appearance is set to Tiles, it is possible to change Tile Appearance to an image. This allows you to do some cool stuff: You can make a material to be a concrete walk, wood wall, or ceiling panelling, and much more.

In the image below, you can see a nested Texture Editor (notice the arrow) for the Tile Appearance settings.

Regarding rendering speed, the Autodesk Wiki Help page includes the following note:

The material render appearances that require the most time to render are (from slower to slowest): metallic paint, flecked metal, hammered metal, water, frosted glass, and perforated metal. Slower render times for these materials are proportional to how much of the scene they cover.

Material Settings Reference

The information below is an overview of several of the material settings and options.

Searching for Available Materials and Assets

When you need a new material, searching the project and Autodesk libraries is the best place to start (see image below). Sometimes a material does not exist, as in this “fence” example, but an appearance asset does; that will get you part of the way there.

Searching the Asset library reveals a chain-link fence option.

When this asset is loaded into a material, it contains several settings, such as image size, cutout, and Bump.

The three images below demonstrate how I created a fence render appearance (visible in realistic and rendered views). First, I did a Google Images search and quickly found an image of a fence that I could tile. Then I made a copy of the image, edited it in Photoshop to yield the middle image below (which took about one minute), and then assigned this image as the “cutout” on the Appearance tab. The black areas in the cutout image are the transparent portions, as seen in the rendered image on the right.

The main image and cutout image were combined to produce the result shown at right.

For the fence example, you would still need to manually add the Identify and Graphics information (for example, the surface pattern and Texture Alignment to make the drafting views and rendered views align). 


This option is great in renderings, as seen with the light fixtures below.

A surface with a self-illuminating material will actually add light to a scene. In the image below, the self-illuminating low wall in the center of the room is the only light source. This material can also be used to get a very white surface when nothing else seems to be working.

Linked Files and Materials

For Revit links, all materials need to be set in the source Revit file. This can be tricky if the linked file is coming from an external consultant. Following the mechanical model image below are notes on how each material was applied.

A: You can set a material in Object Styles to quickly apply a material to everything in the model. This is overridden by the subsequent techniques mentioned below.

B: It is also possible to paint materials on elements. This is required if the color needs to change. For a round duct, you need to paint four separate quadrants for each section of duct. Also, you cannot paint a material on a duct fitting.

C: Most loadable content (i.e., regular families) can have materials assigned as usual.

D: You can also assign materials to the duct or pipe systems, as shown in the image below.

Adjusting the duct material via the duct system type.



One Response to “Understanding Autodesk Revit Materials | Cadalyst”

  1. lpcetra March 3, 2014 at 12:22 pm #

    A great video of about half hour by David R Beach found at http://www.youtube.com/watch?v=OKBmVnS5BxM from Feb 20, 2014. Creating custom Materials, water ootb.

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