Project by : Spiros Koulias

Natrix is one of my projects I did a few years ago when I was training myself to design organic forms in SketchUp. After I found all the proper tools that I needed to design forms with curves, I decided to take part in an international competition for young designers where the topic was Urban Design. First, I thought of designing a wooden bench with uneven curves, which would look like it rose from the ground. I named it Natrix, which in Latin means water-snake because, from every point of view, it looked like a snake moving in space. Another addition to this design I had in mind for the competition was to add three rivers that surrounded the city, and create a dialog between the benches and the rivers, mainly because of their similar shape. At the end of the competition, Natrix did very well and received a Medal of Honors prize among 300 other projects.

It took me quite a long time and experimentation to design this project, and I also tried to use many different tools in SketchUp. At this point, I need to remind you, that SketchUp was not as powerful four years ago, when I designed this project, as it is today. However, the final result that I am about to present to you, came out exactly as I had it in my mind.

I begin designing Natrix by simply drawing a rectangle, and then choosing from the BZ Toolbar, the proper «spline». I draw a curved outline of the shape I want my object to have, and after a few tries and repetitions, I finally got the shape that I wanted, as seen in image 2.

Then I copy and paste the rectangle with the shape I drew, every 50cm. My goal is to paste the item as many times needed so that it reaches the final length I want my bench to have.

Every copy I make, I choose the curved line inside the rectangle, and I scale it up or down until I finalize roughly the shape I want my bench to have. The reason I am doing this, as we will see further down, is that I will need to connect each curve with the next one, in order to achieve that organic form I want. In image 6 you can see the curves I chose in their final form.

And now, the hard part. With the help of the «Curviloft» tool, I will select every curve one by one, and in a row, in order to form a single surface. Every time the «Curviloft» tool recognizes a single line, either straight or curved, it selects it with a different color every time and gives it a number, that appears right next to it. It always starts connecting the lines from the smaller number to the biggest. Once we have chosen the lines that we want, then we hit the enter button on our keyboard.

In image 10 you can see the preview of the final result from Curviloft tool. At the preview phase, there is a parameter bar, where we can change the parameters and the shape of our model. Once we have the final form, we hit enter, and the bench appears as a continuous organic surface in a group.

As we can see in image 12, the whole shape consists of a very detailed design, with too many triangles, which means too many surfaces, which means a very large file. At least it didn’t take long to create it.

Moving on, I wanted along the whole length of the bench, to have 4cm pieces of wood, with the one right after each one taken out. So first, I had to think of a way to cut the whole bench in slices, along with the vertical axis, every 4cm.

To achieve that, I used a simple function in SketchUp, and common sense. I created a large rectangle shape at the beginning of the bench, which will be used as a «knife», and then I copied and pasted it along the bench every 4cm. As you can see in image 16, the whole bench is covered from those vertical slices.

We select all the vertical rectangles, then we right-click on them, and select the command «Intersect Faces with Model».

What does this command do? Exactly what it is shown in the image above. Every rectangle slice leaves its’ outline on the organic form of the bench, every 4cm. This means, that our model is also cut in slices every 4cm.

We can see that in image 19 too, since now we can select every single cut surface on its own. We switch the camera to parallel projection mode, in order to be able to delete easier the pieces that we don’t need, and starting from one side of the bench to the other, I delete every second vertical surface, as you can see in image 20.

After many cuts and a lot of patience, our model is almost done. At least it has the form I expected it to have. But there is one little thing still left to do, which is the thickness of the wooden pieces.

In the images above, you can see the whole process that it took me in order to give thickness to each wooden piece. This was done with the help of the «Joint Push Pull». This tool does exactly what the Push/Pull tool does, with the exception that it can extrude any surface it touches, even inside a group.

In order to create the whole model, I had to extrude each piece of wood separately by 2cm! As you may imagine, it took me quite a long time…!

For the completion of Natrix, I had to add a material to it. I chose wood because it’s a natural material, and can be constructed easier (well I don’t know how easy this specific construction would be, but anyway!)

I was completely satisfied with the final result, as this was exactly what I had in mind before I designed it. With the help of SketchUp and a few other plugins, I was able to complete it successfully. In general, I believe that you can create anything you want in SketchUp. You just need to explore it furthermore.


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