Let's talk about Mesh (part 1)

Since the blog is called What a Mesh!, let’s start by mentioning a couple of things about one of the most interesting features in AutoCAD 2010, called Free-Form Design.

Many requests were coming to the Product Management team about the ability to work with smooth geometry. There could have been many potential approaches for this, and one of the decisive reasons to work with subdivision surfaces was to enable our users to work with a very intuitive approach to modeling. We have seen how 3D adoption has increased dramatically during the last years, and we definitely want to provide our users with tools that will make that transition easy. The fact that Free-Form Design enables you to sculpt mesh primitives with a variety of tools makes it become a very tactile approach to modeling. Sculpting with some sort of clay is one of the first exercises a kid does at school, due to the same reason. It’s intuitive, it unleashes the creative process, and it is fun!

Subdivision surfaces have been around for a while in the Media and Entertainment industry, since it’s a very cost efficient way to represent and render a smooth surface by using a series of planar faces. You can increase the level of smoothness by just a click, and get back to a previous level of smoothness if appropriate. In following posts, I’ll work with specific examples in order to introduce not only the features, but also best practices.

The image below shows a primitive (in this case, a box, to the left), that has a preconfigured amount of subdivisions. We will call this Level 0. The model in the middle is the same box with a Level 1 of smoothness, and the model to the right is the maximum level of smoothness allowed, Level 4.

 

If we refine the smoothed meshes (and we’ll talk about this later), we would get a radically bigger amount of faces in each object. For example, the Level 0 had 64 faces, the Level 1 had Level 0x4=256 faces, and Level 4… guess… Level 0x4x4x4x4= 16384 faces!

 

As you can see, the number of faces can quickly become quite impressive, and, by the way, I really don’t believe you’ll ever need so much level of detail. Best practices are coming in following posts. Stay tuned!

 

 

 

 

Comments

[Nathan]

Hi Guillermo, looking forward to learning from your presentations. As an ACA user I am interested in what, if any and how the mesh modelling can be used in site presentation - showing sloping ground, paths, roads etc. I'm sure you already have a thick agenda for general mesh modelling so I'll be patient but seeing that you already used it for architecture I will wait in hope.

i have found that it's easy to turn a drape into a solid and then a mesh so that's a good start.

Cheers
Nathan

[Guillermo Melantoni]

Hi Nathan, I'll try to cover as many topics as possible. Feel free to ask for more topics, and I'll try to fit them in my already tight agenda of posts. My plan is to post once or twice a week, depending on the amount of time I can get for this task