Help with Roof

smorales02 · 9 Oct 2008, 22:27

Hello again,

Attached is a model of a site I am working on. I have created roofs for two of the buildings (using a ruby I found on this site) I just cant seem to get a roof for the two buildings that connect (called out in file) Can someone please help me figure this out, this is my first major modeling attempt.

Thank you

post file.skp

Gaieus · 10 Oct 2008, 05:52

Hello,

In order to make the script work better, you would need a clear face (or outline) for it. The dividing wall probably prevents you from creating the roof.

I copied the top face of the walls
then temporarily made a group of the building and hid it
pasted the top face back in place (edit menu)
deleted the inner lines so that only the outline and a whole face remained (see it under the roof)
made a little "tweak" (there is a piece of wall extruding from the building and the script could not run because of it so I excluded it)
ran the script and see result attached.
Note that you cannot make a pyramidal roof on top of this building so I made a hipped one.

Finally, a question: why are you modeling in such a small scale? The walls are 0.666" wide only!
Probably this is causing that terrible Z fighting (flickering) effect on most of your walls!

post file.skp

Voder Vocoder · 10 Oct 2008, 07:21

Gaieus,

I have not responded to this request for help before now because I am totally confounded by the Z-fighting, and I'd like to figure something out. The first thing I tried was to scale the thing up to a realistic size. It's almost as if the inches should be feet--multiplying everything by 12 seems to yield reasonable dimensions.

Unfortunately, that didn't help. The Z-fighting is as before and seems completely inexplicable.

Finally, smorales02, adding a roof on those buildings doesn't seem like a big deal. What is the problem you're having, exactly? Have you gone through the many video tutorials that are available? Are you saying you don't have any preference as to the style of roof? It strikes me as odd, too, that you didn't mention the terrible flickering/Z-fighting, or ask for help with that. Didn't you notice?

~Voder

Gaieus · 10 Oct 2008, 08:24

True that even with such thin walls there shouldn't be this terrible Z fighting so that cannot be the only cause.

Interesting however that after grouping the building, it seemed to go away on that particular groupat least.

Then I didn't mention the model being totally out of alignment with the world axes - I know it is (or at least it seems to be) an import but this way it is rather hard to work as I know from my experience before.

Just now, out of curiosity I checked and the model seems to be some 31 kilometres away from the origin so if it is an out-of-scale import, it would be 12 times farther!

Then I tried to move it to the origin but when I do so, I simply cannot zoom on it. Even Zoom extent and the Zoom window tool behaves unexpectedly, jumps here and there and the model is nowhere.

Jean Lemire · 10 Oct 2008, 13:34

Hi Smorales02, hi folks.

First, your model is way too far from the axes origin. This creates difficulties with OpenGL and produces the anoying flickering that looks like Z-fighting. Move everything close to the origin and this problem will be solved.

Second, you model is too small. One of the building is about 69 inches long. This produce a cliping plane problem. Scale it by a factor of 12 to get feet instead. This will solve the clipping plane problem.

Third, you have a lot of layers that you seem to use to isolate geometries. SU layers are more for controling objects visibility. Use groups and components to isolate geometries from one another.

Fourth, the two roofs already built show a strange flickering effect. I will look more in your model when I find some time to see if I can find the culprit.

In the meantime, see this SU file for ideas. In it I moved the model closer to the origin, scale it and purged it to get rid of unused layers, styles and textures.

post file 2.skp

smorales02 · 10 Oct 2008, 14:23

Hello all,

Thanks for the replies.

To start, I did notice that flickering stuff going on but I just assumed it was a graphics card issue.

Second, the original file is imported from a dwg where it is drawn in units. So 1 unit = 1 foot. So therefore .667 units = 8 inches (thickness of walls). I tried to change the units in SU but just got odd results when trying to pull my walls up, 8' looked more like 20'. Do I just need to scale up the whole thing??

Third, when I imported the dwg it came in in its current location, so im not sure what to do about that. In my dwg its in real coordinates so I figured it was in SU too.

Thanks guys, going to have a look at some of the attachments now. Forgive me for my "newbness"

smorales02 · 10 Oct 2008, 14:56

Jean,

I took the file you posted and put all my SU stuff on layer 0 and deleted all the other layers to see if it would help, it seems to have made that "flickering" go away. But how would it work if in the future I want to bring in a DEM file to show the ground surface of the site, seeing how it is no longer in the correct position?

Did I do something wrong when I imported it into SU?

Jean Lemire · 10 Oct 2008, 16:23

Hi Smorales02, hi folks.

When you import a CAD file (DWG for example), make sure that the checkbox labeled "Preserve drawing origin" is not checked. This will avoid the drawing from being imported in SU too far from the origin. This checkbox (and a few other controls) is accessed through the Option button in the Import Dialog Box.

Just ideas.

smorales02 · 10 Oct 2008, 17:07

So by unchecking that box, my model will not come into real world coordinates correct?

Anssi · 10 Oct 2008, 17:32

@smorales02 said:

So by unchecking that box, my model will not come into real world coordinates correct?

No it will not, but it is your only option, as SU is not able to handle coordinates as big as the real world.

Usually problems start to arise when a model is a mile ot two across. If tou have to bring the model back into "real world" coordinates, position it so that the SU origin point is at an easily identifiable spot, to make positioning it easier.

Anssi

smorales02 · 10 Oct 2008, 19:00

would importing it thatn moving my axis make any difference? or is moving the axis only a visual representation?

Gaieus · 11 Oct 2008, 07:49

Ye, most of the cases it is. We often realign the axes to be able to work easier but by right clicking the any of the axes, you can "reset" them

There is a different way of georeferencing in SU: go to your modl info window and set Location there