Monday, September 15, 2008

Rendering in Autocad R2009

May as well put out a positive YES for R2009 here.

R2009 has improved rendering over R2008 : To get a good rendering now, just type in
LIGHTINGUNITS, set it to 2. Apply your materials-if you use realistic shading while doing so, then you get feedback that you have applied the materials.

Turn on Full shadows, then Sun and illumination-sky. You can use the visualising tab on the ribbon-just seems easier than fishing around in menus or typing.

Select the your geographical region, time of day etc and then press render, using say 640x480.

You should be pleasantly surprised. Ok, so not everyone is into rendering....but if enough users start out using the above approach, I would anticipate a huge increase in rendering.

I'm no expert in all this, but it seems to me that this business of "final gather" is involved.
Usually this is set to auto, and sometimes to get it kicked into life you need to set it to ON.

The thing about "final gather" is that, when it is enabled, all the shadows which used to be black, now look a lot more realistic.

Once you get a nicer rendering, save it as a tiff file, I find a resolution of 2400 x 1800 quite good for nice sharp pictures. They can take a while though-15 minutes is normal.

I hope to be able to post a typical rendering of mine soon.

Thursday, September 4, 2008

Blocks versus Lisps

Just plodding my way through one of my drawings today and a thought struck me: I've done this little thing before-a 75mm post with a plate on it's end and 2 x M12 bolt holes to fasten it to a nearby girt. (All in 3D of course)

In the past I have gone on about the need for blocks for every situation-but where does anyone get the time, or the inclination to be disciplined enough to organise a really comprehensive block library?

I am slightly organised now, and over the years the blocks have accumulated like dust in my computer. Maybe it is just that every situation appears to be unique, so things "need to be designed". This might be justifying our existence, or ego.

The other idea I had was that maybe someone (me? when I'm not busy???) would get on and write either in lisp or VBA, general types of lisps-for instance in the above example, you feel the need to do a plate on the end of a post: you initiate the routine and a dialog box comes up with all the variables, plus an option to auto-fill the variables. For instance you might choose a 75 square post: It would then offer up say 10mm as the plate thickness, and M12 as the bolt size and so on.

I'm not sure, but my gut feeling here is that a lisp routine would be better than a block, because the option would be there to change any of the variables before the thing is drawn.

Yet another thought:

Maybe this could all be accomplished using "styles" in the manner of Autocad Architecture: You might have a style named "Plate-75mm-M12" The idea is you insert an object that has all it's settings governed by the style. So when you want one that uses say M10, you saveas the old style then modify the new style to provide M10 holes. (Oops-sounds like redefining blocks!)

All this is most un-Inventorish! After all, what do we spend half our drafting life doing? Changing what is already there. Unfortunately, I would need vast quantities of cash and a promise of a long contract to get into the Inventor club. I was told once that Autocad is OK, but to be really serious, you need Inventor....Hmmmm.

One last gasp here: what if you could somehow link your drawing objects to say a Microsoft Access database? How would it work in practice? Maybe you are in the drawing, and someone says make the holes M10, not M12 in that plate. You issue a special command, click on the plate and you are immediately in the database, right where the plate is. You then alter the hole sizes in there and go back to the drawing, and update the drawing: It is done.

How the heck this would work, I don't know, but it does seem a bit complicated to actually get it to work.

I have already experimented with a house drawing program that uses a text file to generate a drawing of a house, using 3D solids. The plan was to get my drawing outline from the architect, feed all the info into a text file and then press a button. Only trouble was that there would have be a huge amount of work drawing most common types of windows. The idea worked, but I gave up drawing house plans.