What a great subject, this one always gets people talking. There are many methods of modeling geometry for Architectural Visualization. If asked how many people started in this industry with modeling in AutoCAD I am sure we would see many nods, and of those how many remember the fond days of solid modeling? Modeling your geometry is the first of 3 important steps in rendering and I too started out with solid modeling. No really, I hated the changes that would occur as much as you because solid modeling with AutoCAD was very unforgiving in a project work flow. The focus of this article is what works for me as I get asked this question in numerous e-mails from many users.
For the architectural industry it makes sense to use a set of tools geared with architecture in mind. I have modeled with AutoCAD, Form Z, and several other products over the years, but found a tool that not only can do production drawings (construction documents) but also with the power to do object based modeling with architecture in mind. My perfect match was a program called Architectural Desktop. ADT completely changed the way I viewed production drawings and changed my work flow. Simply put ADT uses 2d & 3d "objects", for those not familiar consider the real world example of how a door and/or window fit into a wall system. For more information on this please visit the link above and also your local users group.
ADT is an amazing program and I will not sugar coat the fact that it can be complex and at times overwhelming when you start using the advanced features and designing with the Z coordinate in mind, but with persistence, some reading and a few great resources you can get it to do most anything.
Let's talk about the basic modeling workflow itself:
1. For architectural exterior models I typically start with the building components that are known, typically this involves ADT walls, doors, windows, curtain wall and assemblies, roofs, slabs etc... The "building structure" tends to have numerous design iterations during the early design phase. With the use of a composite building model (each floor stacked on top of each other at their respective height) numerous people can work in and on specific areas of the building design.
Design Note - With the release of ADT 2004 and up you should learn to use the project navigator as this keeps track of the building elements for you.
2. Because of the planned changes that occur and my software choice of VIZ/MAX, I tend to use file linking quite a bit. This works out quite well as numerous people can work on the individual sections of the composite model and I tend to just need to reload the geometry to use the changes. Even with all the powerful features of ADT, there are still areas and times that I prefer the tools from VIZ/MAX. Generally this is to add additional features or details that would be either difficult or time consuming to create in ADT. A few of the toolsets that are very useful include; lofting, scatter, shape merge.
3. At a certain point when the building has reached a “design stop” phase to continue with rendering I tend to break the link and bind the drawings into one or more .max files. From here the building design and construction documents can continue to change and update and I can just focus on the scene at this moment.
While the many various versions and types of software available present different advantages to modeling and rendering I would encourage you to try as many as you can until you find the one that works for you. The ultimate goal is to get a great looking image that represents your building and invokes a feel of the proposed space, and of course it needs to be done in a timely fashion. =)
From here we head towards the most critical part of rendering, these being materials and lighting.