Exporting Revit to 3D Max: How and Why?
Taking our Revit models and/or projects into 3D modeling programs like 3D Max or Maya is quite a common thing to do, especially if we want to render the project with a higher quality and realism or if we want to work on animated walkthroughs. The process is quite simple and we will describe it here, but we will focus a lot more on what happens when the geometry is imported into 3D Max and on what we need to consider when we do this. We will also talk about why 3D Max is a better option for rendering and animating.
How to export from Revit to 3D Max
First off, let’s talk about the process of exporting a project from Revit to 3D Max. In order to do this, open the 3D view in Revit or a camera view (orthographic views won’t let you export the 3D model), go to the main menu, select Export, choose the FBX file format (which is a common 3D format to export to and a format that 3D Max reads perfectly), give it a name and click on Save. As far as the export process goes, this is basically all we need to do. The rest is opening the FBX file in 3D Max and working on it, so let’s take a look now at what we will get in 3D max and at some of the reasons to go through this process.
To import the FBX file into 3D Max, go to the application menu and select Import. Navigate to where you saved the FBX, select it and click Open. It’s actually quite simple as well, but we need to know exactly what happens with the geometry when it is imported into 3D Max so we know what to expect and how to tackle it.
When importing the FBX into 3D Max, the geometry will turn into Editable Meshes, which we can edit at any sub-object level (vertex, edge, face, etc.). Editable meshes allow us to make modifications to their shape in a very simple and convenient way, which is not something we can easily do in Revit, even if we are working with masses or conceptual models. Also, along with the geometry, 3D Max will bring in the lights and cameras that were set-up in Revit, which is actually quite good, since we could dedicate ourselves to just rendering, but this is not always the case. Lights are imported as photometric lights, which work great in Max and give more realistic results, but we might need to remove/replace them if we are rendering with other engines (like Vray) in order to optimize the rendering process (although it’s not mandatory). Additionally, depending on the importing preset you select in Max, you might get a Mental Ray Sun and Sky (Daylight Assembly) into the scene. This one definitely needs to be removed if you render with other engines (other than Mental Ray) or else it will yield unforeseen results, so keep an eye open for this one. In the case of the cameras, these ones are imported as Free Cameras, which we can keep, regardless of the rendering engine we use. We can also change them to match the cameras of the engine if desired.
Keep in mind that even when FBX files can be opened (imported) into Revit, the geometry will be now considered a Mesh in Revit, and all the BIM flexibility/functionality will be lost. This is important to mention since some users make changes in 3D Max (since modeling in 3D Max is a lot easier) and then they want those changes back in Revit. Unfortunately, there is no going back to Revit without paying a price, and the price is not being able to use any of Revit’s tools on the FBX Mesh.
Why should I bother using 3D Max?
Now, why would we want to export to 3D Max? The answer is simple: to create better, more professional and more photoreal renders. Also, to make nicer and more flexible animations/walkthroughs, so let’s take a look at some of the benefits of 3D Max when it comes to rendering/animation.
3D Max offers a lot more modeling tools than Revit, and these tools are a lot easier to use. There is no need to create reference planes or to constraint yourself to 5 different forms (extrusion, blend, revolve, sweep and swept blend) like in Revit. The modeling in Max is very flexible and it basically resembles working with real clay, where you can push, twist, pull or do anything else with the objects. These modeling tools allow us to create more complex and organic shapes with little effort, which is something quite hard to do in Revit (especially organic shapes).
Besides the modeling tools, there are other reasons why we use 3D Max instead of Revit for professional renders:
Revit offers very limited options for mapping textures onto the objects, while 3D Max offers a lot of mapping and UV unfolding tools, which help us to create more realistic texture arrangements and avoid repetition of the same texture on different parts of the object. It even allows us to wrap the textures around the round edges of the model to make them look continuous and natural.
When working in 3D Max professionally, we usually use Vray to render, which comes with its own set of lights specifically designed to work better with it, and to give better results. Lights can be easily adjusted, balanced and even animated, to create more dynamic and interactive results. The lighting quality offered by Vray is by far better than the one in Revit. The good news is that there is now a Vray for Revit, which brings the same quality directly into Revit, but the interface is quite limited, especially if we want to use it professionally and do things like linking lights to objects or changing the contribution of lights individually, so once again, we have to go to 3D Max if we want full control of the lights.
To learn more about Vray for Revit, read the following blog post: Vray for Revit
Revit has a very good built-in rendering engine that has been improved in every release. In fact, rendering in Revit is quite a simple process due to the fact that there are a lot of presets already configured to achieve this, for example: a preset to render with sun, a preset to render with sun and artificial, a preset to render with a sky, a preset to set the quality of shadows and light bounces, and basically a preset for everything. While this is quite handy and fast (not even considering the fact that we can also render on the cloud, which will be another entry in this blog later), the end result is not professional quality (although it is very close). Additionally, Revit doesn’t offer any options to render passes (or AOV’s), which is a must if we want to do post-production work on our renders.
Animation Capabilities are better in 3D Max
While Revit allows us to create simple walkthroughs and render them into a video, the amount of customization we get is quite limited. If you have every tried to create a walkthrough in Revit, you now that it is impossible to open doors to walk into the rooms or to animate lights to change from day to night. Additionally, you cannot have any other moving objects in the scene, like a ball bouncing, running water, a working clock or trees swaying in the wind. All of these things and more, are easily achieved in 3D Max, since it is a software that offers many tools for animation purposes. Your walkthroughs in 3D Max can have walking people, animated lights, moving cars and any other animated object you can think of.
In conclusion, both programs allow you to render your projects for presentation/selling purposes, but the level of customization they offer is what will make you decide which of these two to use. If your primary work is rendering, you certainly need to switch right away to 3D Max + Vray, but if your primary work is designing/documenting and you need a simple way to present your projects, Revit is more than enough to serve this purpose.