Mesh SEO

[Anonymous]

I have spent a few hours trying to model a site plan with paving and curbs. I intended to use a tall concrete wall for my curbs and then use the mesh "paving" raised 6" and SEO subtraction with upwards extrusion to remove the top of the curb wall. This would have given me a 6" curb that would follow the contour of the paving. This did not seem to work. If the mesh is just a surface (no thickness) the SEO dosent work. I then placed a thick slab over the entire site intending to add some thickness to the mesh and perform a downwards extrusion leaving me with a mould to subtract from the walls with, this also did not work. Any one understand what I am trying to do? Mabey the profiler is the proper tool to be using? I just purchased AC so I havent got Archi Terra yet. I know it would help, But unfortunatly I must be done tommorow!? Thank you for all the help guys!

[Anonymous]

As I understand it you want curbs cut to follow the site contours. This is a bit difficult. There is no easy way to do it with walls, but you could make them from meshes.

1. Make one original mesh fit to the ground contours.
2. Make three copies of this mesh and put the original on a hidden layer for safe keeping.
3. Cut up the three copies into streets, curbs and ground (earth, finish grade). Sidewalks may be part of the curbing if appropriate.
4. Lower the streets by about six inches (or whatever your desired curb height is.

When you cut up the meshes, the pieces automatically (unless you deselect this setting) fit to the surface contours and thus to each other.

[Karl Ottenstein]

I use Matthew's process more or less, but came across what seems to be a bug while doing a sloped site mesh last week with a large U-shaped road on it. The U-shape mesh would not subtract from the full mesh. I had to split it at the middle of the U into two J-shaped pieces, and then those two pieces (together as 2 operators) WOULD successfully subtract.

This may affect what you're doing with curbs/etc. if you have concave shapes.

I haven't had time to do screenshots/etc to report this to GS yet...

Karl

[Anonymous]

Karl,

You are right to point out that the complex shapes that site plans produce can be a bit tricky.

It is always good to check the 3D frequently (I find it necessary to do the main part of the work in plan) to make sure that the operations are successful. Even so, I often find I have to fix nodes that get zeroed and generally tweak the site model in 3D.

The important thing is to make sure the meshes don't "go hollow" or disappear altogether due to some illegal polygon or such.

[Anonymous]

Matthew,

I found I could do this without the copies.. I just made a backup copy and cut the mesh, then lowered/raised as needed. How do you cut the mesh with arcs?.. Seems to work only with straight lines.

Thanks.

[Anonymous]

You can use arcs, lines, polylines and bezier & spline curves (as well as fills, slabs, roofs, other meshes, etc.) the trick is that they need to form a closed shape, either by themselves or in combination with the edge of the slab.

If you are punching a hole you can just use the space bar click. You will get the dialog shown in the attachment.

To cut out a shape on the edge of the mesh you will need to use the pet palette, subtraction tool and then space bar click the contour.

The subtraction process is why you need multiple copies. One to cut away the roads to leave the land, another to cut away the land and leave the road, etc.

[Anonymous]

Matthew,

You are right Matthew.. Let me reword my question.. It is possible to run a straight road and sidewalks through a sloping mesh by simply drawing straight lines, splitting the mesh without losing either side, then lowering/raising as needed.. No copies needed as no bodies lost. When I use any line other than straight I am asked to click the break line and side to keep, then nothing is done..

I have so much to learn.. head hurts today..

Thanks Matthew..

[Anonymous]

Yes I understand about using the Split command for straight lines, but I have never had a situation where this was useful for a real terrain model. This is why I only use the other methods.

It is also possible to use SEOs for this but, my experience so far suggests that this should not be relied upon too heavily. I have had a simple (it was still flat - before I added contours) mesh "go hollow" on me when I subtracted a fairly simple foundation from it (walls only - no footings).

But before my suggestions turn your headache into a migraine you should stop and relax and have a nice cup of tea.

[Anonymous]

My local vendor prefers to draw his entire site flat with lines.. then magic wands them into individual meshes, after which they are elevated.... seems pretty good as long as the lot is flat... He then recommended ArchiTerra if I would be doing lots of landscaping.. Your method looking best, not that I ever doubted that<g>

[Anonymous]

My approach is OK for site of low to moderate complexity. For moderate to high complexity or even simple but frequent use, ArchiTerra is probably the best choice.