Terrain Using Skin Command?

[Shrubman]

Hi all:

A couple of weeks ago I asked you all about various ways to get a 2d land survey turned into a 3d terrain model in Lightwave. There were various helpful opinions offered, but most didn't do exactly what I wanted. I had another thought I'd like feedback on.

The method using shades of grey to create a displacement map has the flaw of creating stepped terrain, when using a real life set of contours, whereas I want a smooth mesh. As I've said, I have contour lines representing steps in elevation. Is there a way to convert the lines I have into 3d polylines or something similar and then use the skinning command to drape a skin over these lines or points, giving me the result I'm looking for?

Thanks, in advance...

[riki]

For the best results I think you need to model it by hand.

[Shrubman]

Originally posted by riki
For the best results I think you need to model it by hand.

I'm fine with that idea, but how? How do I accurately transfer the real-life data, in the most efficient manner? This model needs to be accurate.

[riki]

You can load a reference image as a backdrop in one of the orthogonal Viewports using the 'Backdrop Tab' in the Display Options Panel.

Wow I turned 400 today :-)

[John Fornasar]

Take your gray scale map and run it through a blur filter several times. You can then freeze the resulting displacement in LW and manually adjust (using various tools with falloff) areas where necessary.

Head over to http://www.dvgarage.com/ttk.php and check out the Terrain Toolkit samples to see what is possible (DL one of the sample maps and check it out).

[Shrubman]

Ok, I've been listening. I may have to use another method. Humor me a second though.

I just traced my contour map into lightwave using the sketch command. I then placed each contour at the appropriate y-axis elevation, resulting in an accurate portrayal of those contours in the real world.

Forgetting for a moment what the purpose of my work is, can anyone tell me if there is a way to "skin" or otherwaise create a surface using those polys or the points that make them up?

What about spline patching?

Thanks

[SplineGod]

Originally posted by Shrubman
Hi all:

A couple of weeks ago I asked you all about various ways to get a 2d land survey turned into a 3d terrain model in Lightwave. There were various helpful opinions offered, but most didn't do exactly what I wanted. I had another thought I'd like feedback on.

The method using shades of grey to create a displacement map has the flaw of creating stepped terrain, when using a real life set of contours, whereas I want a smooth mesh. As I've said, I have contour lines representing steps in elevation. Is there a way to convert the lines I have into 3d polylines or something similar and then use the skinning command to drape a skin over these lines or points, giving me the result I'm looking for?

Thanks, in advance...

You could trace the contour lines in modeler as splines and then set each spline to the correct height. From there it wouldnt be too hard to spline patch them.

[Shrubman]

Originally posted by SplineGod
You could trace the contour lines in modeler as splines and then set each spline to the correct height. From there it wouldnt be too hard to spline patch them.

That sounds like what I'm trying to do.

First, since I already traced using the sketch tool, can't these be converted to splines using the make curve command?

Second, I tried the above method last night and the picked two points at a time at the ends of two curves and chose make curve to close the area. Does this make sense? The problem is, I'm getting the curves don't cross properly warning.

Finally, what do you recommend for settings in the patch dialog box regarding knots or (the other setting escapes me now).

Thanks

[SplineGod]

When you use the sketch tool it gives you the option to sketch as polys or splines. Once you create the cross sections you then need to connect them with additional splines so you have correct patches. I have a free spline tutorial on my website that I would check out.
http://www.3dtrainingonline.com
Look at the bottom of the page.

[sailor]

if u are not subpatching and u dont care about triangles u can skin them without patching them just select ur elevation polys and hit multiply/skin
aftre that u could try to make a mergetrigon x to create as many quads as possible

voila