Huge terrain issue...

[dimopoulos_d]

I have a problem regarding a rather massive autocad file of a whole mountain.

The dwg file itself is 16Mb and the result of importing it in max is a 100Mb file.

Actually its just splines placed in the correct height, but they are quite broken and refined.

Any attempt to create a terrain (compound) just leads in hours of waiting and waiting, and i dont even know if its in 5 or 50% of the process.

I tried optimizing the spline, i tried welding the broken vertixes, nothing. I just wait and wait for hours.

Its not a CPU or limited RAM problem. I have 2Gb of ram but near 1Gb is used anyways.

 

What do you suggest?

[dimopoulos_d]

Here are some screenshots...

[hughie]

That is one dense bunch of splines:eek:

You could try breaking it into several smaller spline objects and piecing then together afterwards. At least this way would show up which sections is causing the problems.

Alternatively if you want to bodge it you could output from ACAD to a PDF and use fill in photoshop to create a displacement map, but you will loose some of the detail that way.

[Brian Smith]

well it looks like it could take all day to clean and prepare in autocad, but once done right, it shouldnt take more than a few minutes to import into max and turn into a good 3d model. even as complex as this it should take too long. load up or ftp the dwg file and i'll take a long

[ctk111]

First, what interval are the topo lines at? Can you eliminate every other one and still get good results? Not sure if it will speed up the process, but a new loft tool as of ACAD 2007 will give pretty good terrain results. It has worked better for me than Max's terrain tool. As hughie said, you might just want to cut it into sections so it processes faster.

[STRAT]

how accurate do you need to be? you might find some considerable success in displacing a mountian mesh instead.

[gfa2]

Can you eliminate every other one and still get good results?

 

This is what I did the last time I had a project like this. The drawing I had was created with 1 foot elevation increments and 5 foot elevation increments. First I tried the 1 foot and it was pretty clear that it wasn't going to get it, so I tried the 5 foot and it came in a lot faster and it looked just fine.

[dimopoulos_d]

First of all thank you all for your replies.

I must say that i'm not an experienced autocad user.

Maybe there is a solution in acad somehow.

 

I'm not really sure about how much detail i need in there.

The project is about a village on that mountain,

but the houses will be boxlike and the trees shperelike

so I'm not really worried about how "heavy" the whole scene will be.

(or should i???)

 

There will be closeups presenting parts of the village (not too close to the houses),

so, for now i dont want to limit my detail options.

Most likely i will not need full detail, but since i will have to create roads,

and flatten parts of it in order to place the houses, for now i want to keep the detail

and reduce it later on.

 

For starters i think i will try eliminating some splines and see what happens...

 

 

 

 

Here is the acad file, in case it helps...

http://www.photorealistic.net/terrain.zip

[Brian Smith]

well the top half of your drawings is a mess of broken lines with many gaps...the bottom half is pretty much fine. like was asked, how accurate does it have to be. if you want it to be as accurate as possible, you're going to have to spend a good day connecting the broken lines and filling in the gaps. once it's cleaned it should be a really simple process to turn into a mesh.

[jucaro]

where is this located? If you can find a GeoTiFF or a 3DEM version of the site, that would pretty much lessen your load.

[lambros]

well, I am working on a project with a 40mb max terrain file. Fortunately for me, the dwg was very well designed, so I did not have such problems as Dimitris. But to work more efficiently, I applied an edit poly and detached the part of the terrain that the actual buildings stand on, and work with that. The rest of the terrain will probably be multires'ed or optimized for the final renders.

[dimopoulos_d]

I still haven't solved this problem...

But i have another question.

Lets say that in the acad file, there should have been like 200 polylines, but instead they are broken down to lets say 800 lines. Ok with this.

Why when i file link or import this file in max, every single of those 800 lines, is broken down to segment level?

Am i doing something wrong in the import process? I tried the weld setting when importing even with extreme values but still nothing.

Any ideas????

[dimopoulos_d]

I still didnt solve it but i have some extra info.

The lines in the acad file are not just polylines. They are 3dpolylines, whatever that means.

But the thing is that i double checked it, and 3dpolylines that are imported in max are broken down, so what should be a segment is converted to a spline.

 

So the new question is...

Does anyone now if and how i can convert 3dpolylines to polylines in autocad?

[dimopoulos_d]

In case someone is interested, i didnt find a way to fix this problem in 3d studio.

The 3d polylines had to be converted one by one to polylines in autocad through lisp. ( i dont know any details about that cause the conversion was not done by me)

After that everything just run smoothly....

 

Anyway, thank you all for your help guys.

[3danim8d]

Dimitris,

 

Is it possible for you get the triangulated surface from the surveyors or mappers that created the contour file? If they could draw the triangles into AutoCAD for the surface, you could then massage that for your model.

 

It would probably be much easier than working with the contours you were provided with.

 

 

 

Jeff

[mskin]

i think you need to redraw the lines.

 

i would draw splines over the existing lines. To create a terrain object you might not need as many contours as are on your grading plan, so skip a few. for instance if they are 2' increments (wich i know they arent because you are using metric) i might only draw the 10' contours, or the 5' contours.

 

i really think the most accurate way is to redraw them. good luck.

[batteryoperatedlettuce]

If the splines are already decent polylines and all the verticies are nicely welded in max the "normalize spline" modifier could be a godsend. That will pull your vertex count down to a reasonable level

[STRAT]

as i say, cant you just use displacement?

[mskin]

can displacement depict it accurately? what would the procedure be? i have never used it to generate terrain but am curious to give it a shot.