topic Re: Sun study in Modeling

Sun study

Ignacio Azpiazu — Sat, 23 Oct 2004 01:23:25 GMT

I am needing to produce a sun study showing the net new shadow thrown on a park by a new building. If anybody knows any procedure better than what I figured and describe below, in any software, please let me know.

The process requires calculating the shadowed area on the park as existing, the shadowed area on the park with the new building included, and subtracting the first value from the second value, for *about 1400 moments in the year* (one shot every 15 minutes for 27 days each representing a week in a half year).

The 54 sun studies part (27 existing, 27 new) gets taken care of by ArchiCAD, I guess exporting as 2D lines. Then there is manual magicwanding or whatever to highlight the area of shadow on the park itself by getting it into a polygon or zone, and checking what that value is. My optimist estimate is that each moment may take between one and two minutes, which makes the job a 24 to 48 man hours job.

I find it hard to believe that every single sun study provided to the city required a week or more from some unfortunate guy, and I hope there must be some better method.

Re: Sun study

Anonymous — Sat, 23 Oct 2004 13:40:00 GMT

It seems to me that you've figured out the best method. It laso seems that this is a pretty onerous requirement. I would think that a smaller number of carefully selected studies should suffice. Especially when combined with some animated visual studies that AC can produce semi-automatically.

One thing I would suggest is to see if there is a consistent mathematical relationship between the different moments. If so you might only need to to measure some number of key frames and interpolate the others by calculation.

Re: Sun study

Aaron Bourgoin — Sat, 23 Oct 2004 17:53:35 GMT

I am writing to invite anyone who has used Japanese versions of ArchiCAD - or to anyone at Graphisoft, for that matter, to comment on this thread.

Some time ago I was shown an Add-On (in the very early days of Add-Ons) that performed shadow studies in ArchiCAD and prepared data to submit data to the (Tokyo?) building authority. Apparently their requirements were quite complex. What I also recall from this tool was the speed with which it did all this on what would be a dinosaur of a computer by today's standards.

Bearing in mind that the Zone Tool was originally conceived for the German market and addressing Berlin's rigorous space type and quantity requirements for housing projects, would it be too much to consider finding this amazing tool and brining some of its functionality to the broader user base.

Re: Sun study

Karl Ottenstein — Sat, 23 Oct 2004 20:12:16 GMT

Here is a pretty lame idea, but I wonder if it will work to get an image showing the total shadow area. How about setting up a (digital or other) camera on a tripod in front of your monitor and taking a time-lapse photo (basically, keep the shutter open) of the entire sun study animation? Use the smallest aperture and you might need a filter too if you are still overexposed if the animation is very long. You would want to carefully choose your scene materials/colors so that the result gives the mask that you want. (Minimize ambient light I think to boost contrast.) I think the result would be an image with near-black only in permanent shadows, and shades of grey indicating shadow strength as you move towards unaffected areas.

A similar option, taking more computer time but no human time, might be to create an automation script in Photoshop that takes a folder with all of the individual frames of the animation and merges them, one by one (bring new one in as a layer with appropriate blending mode, merge layers, bring next one in, etc.)... ??

Thinking sideways...

Karl

Re: Sun study

Anonymous — Sun, 24 Oct 2004 01:41:47 GMT

Or take Karl's idea about photoshop and think about using a vectorial sunstudy, parallel projection top view. Vector data.

Generate the PMK's and place them in register in your layout. Plot result or draft over the end result showing the net yearly shadow area. How many samples do you really need? Interpolate between dates and times.

Re: Sun study

Rakela Raul — Sun, 24 Oct 2004 02:17:12 GMT

there was a comment from somebody in europe on a city's reqt regarding same subject, no more than a 1 yr back.....maybe it can also help....

Re: Sun study

Ignacio Azpiazu — Sun, 24 Oct 2004 05:28:08 GMT

The requirements I described in the first message (number of snapshots, etc.) are those of the city of San Francisco.

In the presentation the graphics are meant to support the shaded area calculations, and the numbers are what count (they go into a spreadsheet and from there to the Parks authority or whatever). So that movies or pictures won't work unless they are vectorial and with some tracing let me calculate the area using the zone or polygon tool.

Re: Sun study

Anonymous — Sun, 24 Oct 2004 05:31:47 GMT

Well that's San Francisco for ya. Lot of luck with that jurisdiction.

Re: Sun study

Anonymous — Sun, 24 Oct 2004 06:07:22 GMT

Burginger wrote:
Well that's San Francisco for ya. Lot of luck with that jurisdiction.

I assume he is referring to San Francisco Argentina. Is that what you meant or are you thinking of Bagdad by the Bay?

Ignacio wrote:
In the presentation the graphics are meant to support the shaded area calculations, and the numbers are what count (they go into a spreadsheet and from there to the Parks authority or whatever). So that movies or pictures won't work unless they are vectorial and with some tracing let me calculate the area using the zone or polygon tool.

It still seems to me that there are probably some reasonably simple mathematical relationships that should allow you to calculate values between a few measured key frames.

Re: Sun study

Ignacio Azpiazu — Sun, 24 Oct 2004 17:02:17 GMT

Matthew wrote:
Burginger wrote:
Well that's San Francisco for ya. Lot of luck with that jurisdiction.
I assume he is referring to San Francisco Argentina. Is that what you meant or are you thinking of Bagdad by the Bay?

It's the San Francisco Burbinger is thinking of. Luck and temperance.

Re: Sun study

Anonymous — Sun, 24 Oct 2004 17:10:29 GMT

Ignacio wrote:
It's the San Francisco Burbinger is thinking of. Luck and temperance.

Does that mean you might be in the area for ACUWest next year? (Of course, I realize that the schedule is not set yet. I assume it would be in the March/April time frame.)

Re: Sun study

Anonymous — Sun, 24 Oct 2004 19:23:01 GMT

Thinking seriously. Make an appointment with the planning board and /or request a copy of a previous project that they have accepted. This is an unusual requirement, otherwise you are quessing what is actually expected. Besides that, do you want the possible liability of the study? Outside consultants perhaps do this several times a year. Thinking outside the box.

Re: Sun study

Greg Kmethy — Thu, 04 Nov 2004 13:51:29 GMT

Aaron wrote:
Some time ago I was shown an Add-On (in the very early days of Add-Ons) that performed shadow studies in ArchiCAD and prepared data to submit data to the (Tokyo?) building authority. Apparently their requirements were quite complex.

That Add-On is comparing the outline of the shadowed area during the day at a given elevation to a curve that is specified by the authorities. It is using an external (non-graphisoft) engine.

Re: Sun study

Anonymous — Sun, 07 Nov 2004 21:50:40 GMT

"Ignacio" wrote:
I am needing to produce a sun study showing the net new shadow thrown on a park by a new building. If anybody knows any procedure better than what I figured and describe below, in any software, please let me know.

I did one once by making the new building transparent red, the existing buildings opaque. The extra shadow showed up reddish. Does this help?

Re: Sun study

Ignacio Azpiazu — Mon, 08 Nov 2004 03:33:02 GMT

HANIEL wrote:
Ignacio wrote:
I did one once by making the new building transparent red, the existing buildings opaque. The extra shadow showed up reddish. Does this help?

That would save a step or two, which multiplied by a zillion shots would be absolutely wonderful (the spreadsheet still needs to show the areas for the total shadows before and after, but with that method the graphic could be produced in a single step, as opposed to overlaying shots from two sun studies which was what I was thinking of).

So that was straight from ArchiCAD? I do need the output to be vectorial for the calculations. (If it was not ArchiCAD then, maybe with AC 9 and the new render engine it can now be --I am getting 9 in a week or two.)

Re: Sun study

Ignacio Azpiazu — Mon, 08 Nov 2004 03:39:08 GMT

Burginger wrote:
Thinking seriously. Make an appointment with the planning board and /or request a copy of a previous project that they have accepted. This is an unusual requirement, otherwise you are quessing what is actually expected. Besides that, do you want the possible liability of the study? Outside consultants perhaps do this several times a year. Thinking outside the box.

This is *the required procedure* in SF for any building throwing shadow on a park, and I am using a previous presentation by others as a model. The outside consultant has always done it in ArchiCAD, and it takes his staff like 6+ man-weeks! (he admits they are not super expert AC users, and I would guess/hope we might be able to cut some 5 to 5.5 weeks from the critical path thing).

Re: Sun study

Anonymous — Mon, 08 Nov 2004 04:39:04 GMT

This entire thread has been alphabetical, the problem we are asked to chime in about is graphical. Post some material to get our left brain working.

Mark

Re: Sun study

Anonymous — Mon, 08 Nov 2004 09:28:13 GMT

Ignacio wrote:
HANIEL wrote:
Ignacio wrote:
I did one once by making the new building transparent red, the existing buildings opaque. The extra shadow showed up reddish. Does this help?
...
So that was straight from ArchiCAD? I do need the output to be vectorial for the calculations. (If it was not ArchiCAD then, maybe with AC 9 and the new render engine it can now be --I am getting 9 in a week or two.)

It was from archicad, but I suspect using bitmaps. Maybe vector, with transparency in shadows turned on would work Give it a try.

Re: Sun study

Rakela Raul — Sat, 20 Nov 2004 03:50:20 GMT

http://www.cadimage.co.nz/nzarchicad.asp?link=nzarchicad

Re: Sun study

Ignacio Azpiazu — Wed, 08 Dec 2004 00:48:05 GMT

I am not getting color tinted shadows using the Lightworks rendering engine --the sun study seems to just throw 'shadow' fills, even if I make the old buildings in Whitewash and the new building in Glass Bronze. Let me know if it seems that I may be doing something wrong.