Actually this is part one of a series of small tutorials showing how to create a realistic knotted net in 3D. In this tutorial we will create the first knot.

(You can also get all files of this tutorial for free - scroll down to the end of the article to find out how)

Things You Will Need

  • 3ds max or any other 3d software which supports splines and extruding a shape along a spline
  • some experience with your 3D software

Step 1

image3952 In the left viewport create a spline consisting of 12 vertexes(or verteces :D - my spell checker insists on "vertexes") as shown in the image. As you see we are creating a loop. We need more points to the right of the loop as we'll actually run that end of the spline through the loop.
Now select all vertexes, right-click in the viewport and choose "Smooth" to smooth out the edges.

Step 2

image3953 Select vertexes 7-12 and in top-view move them a bit to the left.

Step 3

image3954 This step is probably the trickiest. We'll rearrange vertexes 8 to 12 as if the right end of the spline is running through the loop. I hope the image of the spline with added thickness helps (we'll add volume to the spline in the next step).
If you still have problems with this step grab a piece of rope or a cord and tie the knot for real.

Step 4

image3955 With the spline selected go to the Modify panel and in the Rendering-rollout choose "Enable in Viewport". The "Radial" option should be selected by default. Change the thickness as you like. The rest can be left to default for now.

Step 5

image3956 Select all vertexes except for both end-vertexes. Select the scale tool(R-key), (make sure that the pivot is in the center of the selection!) and scale the knot down. Feels almost like you are actually tightening a knot, doesn't it? :)

Step 6

image3957 If you just want a simple knot you can skip ahead to the next step.
Here we'll create one more "piece of rope" running through the knot. This will enable us to create a whole net in the next phase of this tutorial.
OK, select the spline and on the Modify-panel go to the Geometry rollout, there click on the Create Line button. In the Top view create a straight line perpendicular to the original one. It should be made of three vertexes (both ends and the one in the middle right where the knot is). You'll probably have to move the new line around a bit to get it inside the knot as shown in the image. Also select the newly created vertexes, right-click and choose "Smooth".

Step 7

image3958 Now we'll adjust the shape of the knot. Again select all vertexes of the knot (leaving the end-points unselected) and scale down to tighten the knot. Most likely you'll also have to move vertexes around to eliminate any spaces inside the knot or any overlapping of the rope.
It can be hard to select the vertexes. Switching to wireframe mode (F3) or X-ray mode (alt+X) helps a lot here.

Step 8

image3959 Almost there.
Now adjust the four endpoints. They should be roughly at the same distance from the knot. No need for super precision, just use the grid as a guide. Also bring all four in one plane(in other words at the same height. The easiest way to do so is to select all four and then in the Perspective view scale only on the Z-axes.

Step 9

image3960 Taddaaaa! Get all files of the tutorial for free (you will have to register to turbosquid though. Sorry, wish there was a way around this :) )

Got to part two where we'll start creating a net based on the knot created in this tutorial:

Tips & Warnings