How We Model and Render

This is a general description of the tools and techniques we use on a typical 3d model of a residential development. It's certainly not the only method we use, but it gives predictable results and is fairly repeatable, which is beneficial when a client presents us with a new project and would like to have the "look and feel" of the last one. We also have a detailed project summary, with images, in word .doc format, that we can send for your review. Or you can click here to download it now. It's about a 3.9MB file, but it's a good description of how we apply our design techniques on a "turnkey" commercial buildout project (empty space conversion to full renderings).

Startup

Well, it may seem obvious, but the most important information to have is when the project needs to be done. Over the years, we've learned that this business is very subjective in nature, and what may seem like good results to us are not always perceived quite the same way by clients. So before you start anything, establish a realistic schedule, with milestones that allow you and the client to stay on the same track. Sometimes, our creativity causes us to drift a little, and it's a positive thing because it shows a slightly different perspective of what the intended finished product is. And yes, sometimes we drift to the dark side and miss the intent. So stay in touch, and provide proofs or email updates regularly, especially with a larger project. Also, remember that misunderstandings can be expensive, for both of you! Okay, that being said, let's get to modelling and rendering.

The Project

We have a 10-acre site, to be developed with single family homes. We'll presume for our example that the site is unencumbered (no wetlands, no pinelands, no deed restrictions or easements, no critical habitats, etc). Although the specific site I have in mind actually had all that and more, but that's another story. The homes will have about a 1600SF footprint, not counting the garage, and the lots will be about 20,000SF or so. Because the overall parcel slopes downward, away from the road, the rear 1/3 will not be useable because of utility connection concerns. So....let's see what we have to work with.

Client-Provided Documents

Unfortunately, the client just purchased the parcel, and has only the original survey, showing no real neighboring structures, and it's a faded blueprint at that. We check online and find a tax map of the area, and print it. To get a feel for the area, we go to maps.live.com and get a recent aerial photo. The nice thing about this site (and it's similar to Google maps) is that it also has a bird's eye view for most areas, which lets you see a sort of isometric view that will give you a sense for the "lay of the land" and any neighboring structure sizes, styles, colors, etc. We chose to also model the 4 nearby residences as part of the project, but we'll do them at a low resolution and color them so they are easy to tell apart from the new project. So far, we have a survey, and an aerial photo, neither of which are at any particular scale (and of course not the same scale)

First Steps

To build an accurate model we need an accurate plan. As part of this project, we did the concept plan also, but I'll describe that only briefly. The New Jersey DEP has aerial photos from 2002 of the entire state in a Mr. Sid format (this is a format that is similar to a .JPG, but it's geo-referenced to the NJ State Plane) We locate our project site and download the image (about 5mb, and free!) Whenever we start a project, we always like to have ourselves aligned to the state plane. It comes in handy later when you need to know where north is (not always correct on those old surveys), or if the client requests more services, such as GIS references or whatever. Okay, so we use AutoCAD Civil 3D and start a new drawing. We use the Map menu to insert an image (not the Image Manager! you'll see why) that is aligned to the state plane. Now, the only problem with that image is that it's a sort of infrared image in that all areas that are green show up as red, presumably so they can identify areas of potential wetlands. In any case, the image comes in at a 1 unit = 1 foot scale (so if you're using arch. scale or whatever, you'll be confused...just set your units to decimal for this)

Because we are going to overlay our finished model on the live maps image (which is all natural color), we need to bring that image into AutoCAD using image manager, and scale and rotate it until it overlays our "infrared" image just right. Don't spend too much time on this part...the overall error if you don't get it perfect should still be less than 1%. Now that you have the true color image in place, use the image manager and detach (or just unload) the DEP image. Next, scan the old survey, and using as many benchmarks as you can find, overlay that image with the color one. Voila! You now have a decent base to trace and quite accurately draw your new plan. Set up all your lots and curbs and roads and sidewalks, using separate layers (and keep the names short, as one of the software packages we use likes to truncate long layer names)

Now before we go too far, you need to use a little math here....if you are simply doing a concept plan and 2D color rendering you need to determine your output size vs. your model size. For example, if you need to create a 24x36 color rendering of the site, and it's say, 1000' x 400', then each foot on the finished product will represent 500 feet of real world. When you do a little division, that means each inch will be about 40 feet in real life. Conversely, each foot of real world will only be printed at less than 1/32nd of an inch. The reason this is important is that, in this example, anything on the site that's less than a foot in size will barely be visable on the final print, so you'll have to trade off how much detail you build into the plan view vs. how much anyone would really notice on the finished product. For full 3D models, renderings, and animations, you should avoid detail on anything under 4-6" or so (the reason for the difference is that particular segments of an animation or rendering may get very close to some items and you wouldn't want them to look choppy or blocky)

The Basic Geometry is Done - Now What?

Now that the site is complete in 2D, you will create a rectangle to encompass it, adding 20% or so to the site size. For our example, the 1000'x400' site will now be enclosed in a 1200'x480'rectangle. You need to remember this size, because it will come in handy a little further along the process. What you've just done is define a boundary for a texture map that will be applied to the 3D model later.

The next step is to setup a raster plotter for AutoCAD, and set the resolution of that plotter to 8000x8000. We use the Targa file format, because the color depth is good. Now you will plot the current drawing using this new raster plotter and save the file where you can find it (be aware, the file you'll be creating will be about 64MB). For plot settings, choose "window" and use the lower left and upper right corners of that rectangle, and make sure to specify "scale to fit" in the plot dialog. Oh, and if it's not too late, make sure that what you plot is just the linework...no text or dimensions or hatches!

Using AutoCAD Drawings as Texture Maps

Well, let's close AutoCAD and open Photoshop (or your favorite, but robust, paint program), and then open the raster plot file you just created. The first thing you notice is that it does not contain just the window you defined, but rather a square that contains your rectangle. Use the cropping tool to clip the image to the actual edges of your rectangle. By the way, if you are having trouble seeing the image or the rectangle, you may need to change the colors of those objects in AutoCAD and then replot. If any of the colors you use are mapped to "black" or "white" pens in the plotter's color table, they get sent to the raster file as the same color as the background, thus invisible.

Paint!

Now use all the tools you can to create an effective color image by painting over the AutoCAD linework. Be sure to create new layers for each item you paint, such as "roof", "pavement", "mulch", "tennis", etc. This will make it easier to touch it up when you're done and find you don't like parts of it.

You're At a Crossroads

At this point, if the AutoCAD file included landscaping, it could also be painted in, but we will skip this part and opt for our landscape to be created in Vue 8 (more on that in a bit). So if all you needed was a 2D rendering, finish painting it, flatten the image and save the file (but save the layered .PSD version also!) as a JPG image. Now we go back to AutoCAD, and insert the image, using the rectangle from a few steps back to locate, scale, and rotate it into place. From here, use draworder to send the image to the back of the display stack, and adjust AutoCAD's layers and colors to give a nice composite view, and print to your favorite color printer. In the 2D world, you're done, but again, this will be a 3D model and rendering, so off we go to the next step.

3D Modelling and Beyond

Now to the fun part (and sometimes the most challenging part). There are many different methods of building 3D models, but we use a combination of software. Rather than go into detail about using the software, let's just take a look at our next few steps. Since this will be a fairly detailed model, We will use Chief Architect to create the house model (Autodesk's Arch Desktop or REVIT is a great alternative, but we haven't made the investment yet). Chief lets us very quickly set up defaults for windows, doors, etc., and has a pretty extensive library of 3d symbols. For our project, there will be two versions of the homes, a "leftside garage" and a "rightside garage". Obviously we're only  going to draw one version and then mirror it. Once we're happy with the house and furniture/accessories layout, we shift to a 3d camera view, and export the file as an AutoCAD .DWG file.

At this point, we should also mention Sketchup. We use the Pro version, which gives access to thousands of online (and free!) models. So what we can't find in Chief's extensive library, we can import directly from sketchup. Chief also permits direct import of .3ds and .dwg files.

Back to CAD

Back in AutoCAD, we open our site plan, and then insert our saved .dwg file from Chief, but don't explode it! It's got way too many faces (some of which are hidden) to work with right now, so we move it off to one side, explode it and go through the model layer by layer, deciding which objects can be simplified or removed entirely. Oh, before you do this, set the AutoCAD variable SPLFRAME to 1 (type SPLFRAME at the command prompt and enter 1 as the value). This will force all those hidden edges of 3d faces to display. From here, the most labor intensive work begins - the building of the site in true 3D. We've written some proprietary routines for AutoCAD over the years that let us create a fairly detailed site model quickly. That, and the use of Civil 3d's DTM routines to create the terrain model. When we're happy with the terrain, we mirror our house and copy it as appropriate. The last step in AutoCAD for this project is to display the terrain as 3d faces, move our rectangle to the same layer as these faces, then save the file.

Let's open 3DS Max, and import the AutoCAD drawing into a new scene. To get the abrupt terrain/material transitions on the site, such as at curbs, retaining walls, etc., there are several options. Our two favorites are to either make the curbs extruded solids in AutoCAD and then do a Boolean Intersect in max, OR to use the curb lines to create 3D sweeps in max. Since the latest versions of AutoCAD also permit the conversion of meshes to solids, there are several options to creating smooth terrains. To be honest it really depends on the site and number of these objects you have. For our project, we'll go with the AutoCAD extrusions, and then further modify the resultant faces by extruding them to the curb or wall height in max. By the way, a short digression here.....if you export from AutoCAD to .3ds, the curved objects don't look so smooth, so it's better to actually open the .dwg file in Max and then export the .3ds from there.....just a tip. You may also want to read up on the Viewres, Facetres, Isolines, and Surftab variables in AutoCAD, as these will affect the geometric accuracy of the model you build and export.

Material Madness

Now we move on to painting and texturing the objects in our model. Here's where that number you remembered from the raster plotter rectangle comes in. Select the object that is the 3d-topo in the scene and apply the .JPG rendering we did earlier, but rather than using a tiling value, use "real world values" and enter the size of the rectangle. You should now see the rendering draped over the topo/rectangle object. And it should match very nicely. So we assign some additional colors and textures to our buildings and other objects, add some lights, and a camera and render! This phase is iterative, of course, while you adjust lighting and material settings to where you want them. If you have access to a 3D painting program, you can further tweak the image map of the site.

Okay, we're getting close now. For realistic terrains and environments, we have two choices of software, Vue 8 and Worldbiulder Pro 4.0. Both of these work as plugins to 3ds max, so it's simply a matter of choosing the effect we are looking for. Both softwares also work as stand-alone solutions.

Worldbuilder offers a wide range of landscape modifiers to simulate erosion and complex terrain textures, and it also has some really nice rivers, waterfalls, and other environmental effects. The limitations to the software are that the plants and trees merely approximate actual species. Also, our attempts to get support from Digi-Element have been futile. It would seem the software will be discontinued. This is a shame because we were one of the original Beta testers of this software, and it had the potential to corner the market.

Vue 8 is the latest release of the most outstanding landscape and terrain software we have ever seen. The features are too numerous to list, and we continue to find new surprises every time we use it. The plants are extensive and true to real species, and the environmental and atmosphere effects are superb. The ONLY limitation we have found is that there is no built-in method of generating particle systems (like waterfalls, fountains, or rain and snow). E-on software has indicated they will most likely implement this in an upcoming version. In the meantime, the terrain sculpting tool can let you "carve" your terrain while viewing the 3d model you've imported.

It's time to open 3ds max, and start the plugin of your choice. This is the first time we've opened another software package and didn't export or import anything. That's because our two landscape modelling solutions also come as a plug in that communicates with Max, so the first thing we do is activate the plugin, then open max and our model file, and activate the corresponding plug in for max. From this point on, all rendering we do will use both programs and a little trick called a Z-buffer to render items separately and then join them into a final, seamless image...or animation.

That's It!

Define some camera and/or target paths, setup network rendering if it's a big model, and we are free to catch a movie or get that lawn mowed! Our projects range anywhere from 8-100 hours of rendering time, and our example here is projecting about 56 hours. But, as it's a real project, you might find it here as part of our portfolio once we've cleared it with the client.

Good luck and happy rendering, and if you have any questions, we'll do our best to help. The entire project as I've described it here took about 12 hours to setup, exclusive of rendering time. And yes, parts of it were real work, but mostly it's just fun, and satisfying when you get compliments on the finished product!

Software Used: AutoCAD 2011 Civil 3D, Photoshop 6.0, 3ds max 2011, Sketchup Pro, Chief Architect X3, and Vue 8. Admittedly, that's around $10000 worth of software, running on around $2000 worth of hardware (our current renderfarm uses 4 pentium-based systems, 2 of which are core duo). For best results, single systems should be quad core, 16gb ram (Windows 7 supports over 4GB), 1gb or better openGL video, and a large hard drive (min. 120gb free) to handle all those stills and animations. As a guide, our sample project took a little over 4 hours to render a single image with full radiosity at 2000x1600 pixels on a 4GB laptop. We also prefer dual monitors....our modeling system has two 24" monitors.

As a side note...our best system is a dual core running Win7 , 8gb ram, 1gb openGL video, and a 1tb hard drive. Believe it or not, when we render in Vue 8, it warns us we may not have enough memory to continue (but we have yet to have an issue on several dozen animations)