topic Re: Screening in Modeling

Screening

Stephen Dolbee — Tue, 11 Nov 2003 22:42:31 GMT

Does anyone have any ideas/suggestions for simulating screening in elevation view? Partially hide what's behind?

Thanks,
Steve

Re: Screening

Karl Ottenstein — Tue, 11 Nov 2003 23:10:59 GMT

Stephen wrote:
Does anyone have any ideas/suggestions for simulating screening in elevation view? Partially hide what's behind?

Hi Steve,

Just use a 25% fill with no border and a white pen for the dots (for starters). This fill alone may serve your needs if you also create several additional white pens that are fatter and fatter and combining the fill and pen to get the level of screening you want.

I use screen-fills like this to partially obscure foundation elements in elevation.

HTH,
Karl

Re: Screening

Anonymous — Wed, 12 Nov 2003 00:11:01 GMT

Steve

I use a similar system to Karl, with a borderless fill of 45 degree white stripes to partly block the foundations of elevations which are generated straight off the model, makes all the lines look dashed.

Tip: Make the fill by pasting stripes made of 'Solid Fill' into a new symbol fill, then you do not have to worry about the pen weight of individual lines, the stripe width being part of the fill.

regards

Re: Screening

Karl Ottenstein — Wed, 12 Nov 2003 00:56:48 GMT

Bill wrote:
a borderless fill of 45 degree white stripes to partly block the foundations of elevations which are generated straight off the model, makes all the lines look dashed.

Great tip, Bill. Picture says 1000 words.

My first reaction was "but the fill will completely hide some of the foundation linework that shows stepped foundation footings or struts" ... and the answer is (duh), to have a 135 degree version also. I'll still use the uniform screens in other places to fade elements at different opacities, but I'm going to switch to your technique for foundations.

Thanks!
Karl

Re: Screening

Stephen Dolbee — Thu, 13 Nov 2003 14:12:52 GMT

Thanks! That does the trick.

Steve

Re: Screening

Link — Thu, 04 Dec 2003 05:29:16 GMT

Has anyone figured out a clever way of using this method while also using vectorial sun shadows? Obviously we don't want shadows below grade.

If not, I'm guessing it's one for the wishlist, but where does it end??!

Cheers,
Link.

Re: Screening

Pete — Thu, 04 Dec 2003 14:14:28 GMT

If you unlink, Link, you can draw a polyline for the grade level. Then select all below the line and Split. That way, the shadow fills are split at the grade line and you can delete the lower portion. You can also select the foundation lines that are below grade and simply change the line type to dashed.

I hate unlinking though.

Re: Screening

Karl Ottenstein — Thu, 04 Dec 2003 17:36:07 GMT

Pete wrote:
If you unlink, Link, you can draw a polyline for the grade level. Then select all below the line and Split. That way, the shadow fills are split at the grade line and you can delete the lower portion. You can also select the foundation lines that are below grade and simply change the line type to dashed.

I hate unlinking though.

I hate unlinking, too, Pete.

In any case, there's a problem with the way that GS implemented the split operation with fills IMHO.

Take a look at the attached image where two fills were split using the very simple line shown (avoided curve just to make this more obvious - but it happens the same with curves) ... and then the bottom pieces were dragged down for illustration.

Note that the first fill is split at the first intersection point and using the angle of the line at the point (or tangent I believe when it is curved) ... rather than adding additional points and giving a polygonal split. The second fill, being split only by an unchanging line, splits fine of course.

I suppose I'd add proper polygonal splitting to the wishlist if I did this often (go for it, anyone who does!), but haven't so far ... however your tip on breaking out sun shadows might encourage me to do so in the future, even if I just paste the unlinked shadow fills back onto a linked elevation.

Thanks,
Karl

Re: Screening

Anonymous — Thu, 04 Dec 2003 18:49:24 GMT

Don't use split, use subtraction on the pet palette.

Re: Screening

Karl Ottenstein — Thu, 04 Dec 2003 20:31:50 GMT

Matthew wrote:
Don't use split, use subtraction on the pet palette.

Subtract only works for one polygonal element at a time - whereas split works for multiples. If you select multiple fills (or slabs, or ...) and try to do a subtraction, only the first one is affected.

With the split command, as Pete suggested, all fills can be selected, invoke split, then just click on the polyline and select a side. Quick and simple ... except for the split bug shown in the screen shot.

Karl

Re: Screening

Anonymous — Fri, 05 Dec 2003 01:24:32 GMT

Karl wrote:
Subtract only works for one polygonal element at a time - whereas split works for multiples. If you select multiple fills (or slabs, or ...) and try to do a subtraction, only the first one is affected.

With the split command, as Pete suggested, all fills can be selected, invoke split, then just click on the polyline and select a side. Quick and simple ... except for the split bug shown in the screen shot.

Karl

True, but if it doesn't work a few quick (magic wand) subtractions isn't too bad.

Re: Screening

Link — Fri, 05 Dec 2003 05:32:45 GMT

If you unlink, Link, you can draw a polyline for the grade level.

I'm just not an un-linker - I just can't bring myself to do it!

Thanks for the suggestion though Pete.

Cheers,
Link

Re: Screening

Karl Ottenstein — Fri, 05 Dec 2003 05:51:22 GMT

Matthew wrote:
True, but if it doesn't work a few quick (magic wand) subtractions isn't too bad.

I shouldn't quibble, Matthew, but hey, I'm 2 posts from 200 so I might was well get closer and see what three house icons gets me.

The problem with magic wanding, as shown in the small example many posts back, is that when split cuts a polygonal element, it may well cut too much. If you delete the parts below the line (the parts dragged below in the screenshot) - there's nothing to magic wand. One would have to use the add-polygon button and redraw the missing piece(s). If you leave the split pieces in place in order to use them as your magic wand target, you don't know where the bad splits are to correct them without selecting each fill in turn ... although I suppose a workaround there would be to select all of the split-below-the-line bits and change their color or something like that.

With sun shadows and complex eaves/beams/etc - there can be tons of polygons to split/subtract/whatever in a bad case. With mountain slopes with steeply curvy ground lines, this would be a real pain.

Cheers,
Karl

Re: Screening

Djordje — Fri, 05 Dec 2003 07:26:31 GMT

Karl wrote:
In any case, there's a problem with the way that GS implemented the split operation with fills IMHO.

Workaround: use MagicWand to create new polygons below the split line/polyline/curve/whatever and then remove the extra part of the original polygon.

Re: Screening

Anonymous — Sun, 23 Jan 2005 06:27:24 GMT

Bill this tip is great! In regards to dealing with the shadows I create a grade with the attached settings below. Note the section fill is set to a fill as described above and the mesh body or volume needs to be a transparent material. This works pretty well however if the site is rather step the Elevation marker on the uphill side is a problem do to the grade getting in the way of the building. My solution is to jog the Section/Elevation marker in and out just beyond the roof facia. Another problem is the display order is re-shuffled everytime the elevation is rebuilt thus you need to move the grade to the front and then back one so that the 2d stuff is not screened, prior to each time you want to upgrade the elevation in plotmaker otherwise the foundation will not be screen. And of course the foundation need to be modeled accurately I guess I would rather deal with the above problems then unlink the elevation. TO LINK OR NOT TO STAY LINKED STAY LINKED AT ALL COST!!!!! Any refinements or better ideas would be greatly appreciated.

Jim

Re: Screening

Anonymous — Sun, 23 Jan 2005 06:32:27 GMT

Here is an example note that the fills on the elevation markers below grade are screened( forgot to send the grade back one level). Still would rather not unlink.

Jim

Re: Screening

Anonymous — Fri, 28 Jan 2005 04:17:29 GMT

Hello,
Here is a possible alternative for making presentable elevations
with dashed lines for subsurface elements without unlinking.

I have made two very simple 2D objects, one draws a strait dashed line,
the other draws a vertical frost or basement wall edge line and a footing
shoulder. Unlike the "Dashed" line type, these two objects fill the gaps
between the dashes with a line segment that is the color of the project
background color.

While the mesh is temporarily made transparent or hidden, these
objects are used to draw over the edge lines of subsurface elements.
After all objects are placed, they are brought to front, and the mesh
is returned to it's former material settings or un-hidden.

These objects appear on top of the mesh fill and on top of the subsurface
elements and hide their edge lines and therefore the section/elevation
need not be unlinked in order to edit line type and pen number.

I also hate to unlink.

Thank you,
Peter Devlin

Re: Screening

Anonymous — Fri, 28 Jan 2005 08:43:20 GMT

Notice that this thread was started a while back but...

If you want dashed lines for subsurface elements just trace the grade line with the marque then complete the fenced off area to include the sub surface elements.

Nudge the Marqued area so it is slightly below the grade line and choose Tools/Create Patch

Select the patch and choose File/GDL Object/Open Object

Open the 2D Symbol window, Select All, change the line type to Dashed, place a few meaningful Hot Spots. Done.

You can do a VERY large building this way in less than 20 seconds.