Friday, June 27, 2008

Drape & the Shadow

The aussie planning codes for residential construction give the council the right to request shadowing information of your proposed construction and the impact on neighbours and ACA gives you some great tools to produce an image that will not only give the required information but do it in a format that is very impressive. Dermot has sent me this image from a project of his which demonstrates several features of using ACA. The first is the site model constructed using the humble DRAPE command.
You can obtain a 3D model of your site by placing the contours at their respective Z levels and issuing the Drape command to give you a contoured MassElement. You can then model up other ME's to union & subtract with the base model to create other features. Using ME Groups you can create some objects as negatives that will deduct space live from another ME allowing you to make constant changes without making anything 'hard' allowing you to experiment. On Dermot's pic you can see he has cut out for driveway, a rear swimming pool and yard area (circular) and it gives you a great overview of the site levels.

TIP: If you give your ME an earth texture in section, it can be also used in your sections (and elevations). To trim unwanted 'earth' you can use a styled aecPolygon in your view file set to mask or just having a white background (check your plot style). If you wanted to further limit the area of 'earth' that is hatched, you can use the 'Material Boundary' tools to limit the area of hatching or even the ME itself. Perhaps that could be an article in itself. Oh did I mention that you can attach a grass material to the ME (presentation high detail DispRep of course) for rendering as well.

Display Reps for rendering and modelling.
The second item that Dermot's image illustrates what James showed us earlier. To have one DisplayRep with only a simple material universally applied, you can use it for illustrations that don't need any materials showing. Have you played with this concept? I have since James brought it up and resolved to add the materials in the Presentation DR (High Detail) and have the Medium DR (Model) left as one Material) although as James pointed out and Dermot has also done, you can add your glass material to windows. Further experimentation is now easy to find that one material you like. James used white, I've seen an image using a wonderful cardboard texture so that the image looked like a carboard model. I have lots of textures in my library and depending on the purpose it's very easy to swap that one material in and out.

Shadow Diagrams
The third item that Dermot's next image illustrates is of course the shadow diagram. Using the rendering tools you can set the sun in it's correct position, at the correct time of day at the correct time of year just like the codes ask for. The actual rendering side of things is too big for this article and as admitted before I ain't no expert with the new rendering engine but you can download Autodesk's own James Smell's great pdf on this topic.

Using a photoshop type program (Gimp for free)you can add the text etc OR you can bring the rendered image (.jpg) back into ACA to set up in a view port and easily add your text there in a familiar environment. You can use the Image command or just drag & drop! Too easy!

I've only skimmed these items so if you want some more explanation for how then let me know by posting a comment. But also have a good look at the ACA help (yes it can be very helpful) and also the tutorials. I had to download the tutorials for ACA08 and I see that I have to do the same thing again in 09! Curious! Can't fit them on the 2 DVD's? Maybe they are done after the date? Download 07-09 tutorials here.

No comments: