Question About Drawing Lines in Sketchup

[Tom Kay]

Hi Everyone;

 

First post in this forum. Nice to "meet" you.

 

I really need to make the leap from 2D to 3D drawing or modelling. I want to draw both home renovations and homebuilt aircraft designs, all for fun. Of course, I'll use the home reno drawings to visualize what my home will look like when I'm done with the alterations, before I actually start ripping out walls.

 

The problem is that there are so many 3D modelling software systems out there. So I've decided to start cheaply, with Google Sketchup. Hey, it's free. I don't mind spending a couple hundred bucks later, if I see a real need for something better, but for now, I'm just getting my 3D feet wet.

 

I have drawn with Corel Draw 2D for years, and I love the program. It's really intuitive, while AutoCad LT 2005, for example, was a nightmare for me. Why? I just found it cumbersome and unintuitive. Too many steps to do one simple function.

 

I have started with Sketchup and I'm running into problems already. I'll just say that at first, I want to be able to draw basic straight lines, or gently curved lines and know where they are in 3D space, and how long they are. The lines don't necessarily have to be parallel with any of the 3 axes. I can't even seem to do that. So, let me ask, is there a way to draw a straight line, and definitively know the XYZ co-ordinates of the starting point, and the end point? That would really help. With that, I could do a line, then add a second segment, third, forth, etc., and make a curved line, similar to a 20 car train. Each car is straight, but when it's sitting on a curved railroad track, it all looks curved to the observer.

 

So, can we draw lines with full knowledge of the 3D location of the end points? I call it XYZ space, but I guess SU calls it red, green and blue. I'm not sure what colour corresponds to which axis, x, y, or z, or if that even matters.

 

Let's start with that, and thanks. Tom Kay, Ottawa Canada.

Edited May 28, 2009 by Tom Kay

[Burk]

No need for that. The way Sketchup works is not CAD like with coordinates. The colored axses give you the directions you need and the vcb box is for giving the lenght. In this way you can get every single point in the space. But take a look at Scetchucation. There are several scripts that will help you out to set points, lines and faces easier.

 

This should help also. Try out the intersections, a great Sketchup feature.

Set the axes like you want ( change them easily if you are out of them)

Set construction points and lines for endorsement.

 

But essential is: Learn to think in a new way how to model.

Away from the technical modeling in CAD to shape modeling with a geometrie background.

[BillyElNino]

I would also add that you need to move away from lines and think about the polygons and objects that you are creating, rather than creating a 2D line drawing you are creating a 3D model, which will consist of the faces you set out. With this in mind SketchUp will be easier to comprehend I think.

 

Start free modeling simple objects and shapes and work from there to familiarize yourself with the many (simple and straightforward) controls rather than jump into modelling your living room straight off.

 

Any problems you have I'm sure you'll be able to get them answered here but for the beginner there are many free video tutorials from Google themselves to get started with.

 

(and from your original post, there is no coordinate system, or to be 100% accurate, there is a coordinate system but, to make it 'simpler' to use, it is hidden from you)

[Tom Kay]

Hi Burk and Billy;

 

Thanks for the replies. This whole world of 3D modeling is completely new to me, so I admit that it will be tough to unlearn what I have done in 2D. I'm also going through a process of seeing what 3D software is user friendly and intuitive (from my uninformed perspective), and this includes my current front-runner, Rhino.

 

In Rhino, I was able to (awkwardly) put together an aircraft fuselage tube frame, fairly accurately, rotate and view it as I'd hoped, and then render it. I was hoping that I'd learn quickly with SU to do the same, but perhaps the way SU works really is different.

 

I'll keep pluggin away at it.

 

Thanks again, Tom.

[BillyElNino]

put together an aircraft fuselage tube frame

 

just did a little test on this in SketchUp, you can use one of the Sandbox tools ('from contours' tool) to create aircraft fuselage. As I understand it what you want to create is actually quite a common 3D command, its called a Loft, in basic terms in most 3D applications you create the bones (or the airframe) and then loft the skin over it using the bones as the guidelines for the skin. Its an automated process. Have a look at this images attached. SketchUp is quite crude for this but it is definitely possible and semi automated (although I am sure there are scripts to do it completely). In more advanced programs it will be quicker and fully automated. (I would bet that Rhino could do this but I don't know).

[Tom Kay]

Hi Billy;

 

Thanks again for diving into this. I have been busy too, doing a little artwork, although (Bless me Google, for I have sinned) it's with Rhino.

 

After around 3 hours of practice I've created a tube fuselage and rendered it. I'll add it to the post so you can see.

 

I do like what you've created, and adding skin is a whole new area for me that I haven't tried yet.

 

I suppose at this point I should admit that I'm starting to lean the Rhino way. This doesn't mean that I'm done with SU, but for now, I think I'll focus on one system. I appreciate all the assistance, though.

 

Cheers, Tom.

[BillyElNino]

I'd agree with you about moving away from SketchUp, especially for something thats as detailed as Aeroplane modeling. I use SketchUp for the basic modeling of buildings, anything complicated I do in Cinema 4D afterwards...