In this tutorial, I’ll show you how to create accurate, bendy hose and pipe using a free plugin called BezierSpline, and the Follow Me tool.
I recently modeled a small utility closet in my RV, because I was going to install a water filtration system and wanted to make sure everything was going to fit in place. Modeling it in SketchUp allowed me to visualize how I was going to run everything, and also let me measure the length of hose I would need. The majority of the model is hose, bent in various curves.
Watch the video, then continue below:
To create a basic pipe, you need to create a path along the center point of the hose you want to create. For a simple curve, you don’t need any special plugin, you can just use the arc tool.
Next, draw a circle at one end of the hose to represent the profile of the hose. Then, select the curve path, activate the Follow Me tool, and click on the face of the circle. The hose will then be created, and you can triple click it and make it into a group.
That’s great for a simple curve, but what if you have a somewhat complex curved hose you need to model?
The BezierSpline Plugin
The BezierSpline plugin allows you to draw curves with multiple control points that give you the ability to create very smooth, multi-dimensional curves. There’s a much more mathematical explanation to Bezier curves which I won’t pretend to understand. The curves are created automatically in relationship to the control points you place. This tool is the key to being able to create accurate hose, bending in all sorts of directions.
Download PluginTo install the BezierSpline plugin, I recommend installing the Sketchucation Plugin Store. It’s a great way to manage all of your plugins, but it also gives you access to many more plugins than what you can find on the SketchUp Extension Warehouse. Once installed, you can search for BezierSpline in the store, and install it from there. More more info, see here.
This plugin is “Donationware.” It’s completely free to use, but if you find it valuable, the author accepts donations as a thank you. Bezierspline was created by Fredo6, if you’d like to donate to him, click the donate button on the plugin page.
The plugin includes a number of different tools, but the one I use the most is the first one in the toolbar, the “Classic Bezier Curve”. Here’s a basic rundown on how to use the tool:
- Click once to define the start of the curve.
- Click again to define the end of the curve.
- Now, you click where you want to place control points, keeping an eye on the small yellow triangle, so you know which side of the curve is being affected by the control point.
- On your last control point placement, double click to tell it you’re done placing control points.
- You now have the opportunity to adjust the positions of the control points. Once you’re happy, click once more away from the curve to complete it.
Creating hoses and pipe
The key to creating hoses and pipe with the Bezier Spline tool is to place temporary guides in your model to snap the control points to. The best way to do this is to create a component for the ends of your hose (like, the fittings that are going on the end of the hose), then place the guideline inside that component. They don’t have to be anything fancy, they can just be a simple circle, extruded. Once the component is created, you can rotate and position it in place, and the guideline will rotate too (since it’s in the component), giving you a point of reference for your control point that is in direct relationship to the orientation of the hose end. This is what makes the curve smooth.
Once the ends of the hose are in place, you can use the Bezier spline tool to anchor the start and end of the curve, then click on each guide point to anchor the control points.
From there, draw a circle on one of the faces of the fittings and use the Follow Me tool to extrude the hose.
Tips and Tricks
- Group it – Once you’ve created the hose, make sure you triple click, right-click, and make it a group or component that way it doesn’t stick to anything else in your model.
- Find the Length – If you’d like to know the length of the hose you just modeled, right click on the hose and hide it. Then select the original curved path, and go to Window -> Entity Info and you should see a length measurement. That’s why one of the reasons I don’t delete the path once I’ve created the hose.
- Editing – The easiest way to edit existing hoses is to delete them and start over. You don’t have to actually delete the bezier curve, you can right-click it, and edit it. You’ll be able to adjust the anchor points and control points for the curve. Once you’re done, re-extrude a profile to create the hose. This is the other reason I don’t delete the curve after extruding the pipe.
- Precision – You’ll notice that the hose does not end exactly perpendicular to the hose fitting. This is because the first part of the curve segment isn’t perpendicular to the fitting’s face. If that’s important to you, you’ll have to start from each fitting with a small line segment, then build your bezier curve from there.
- Automation – For more automation of this process, check out the PipeAlongPath plugin, by TIG. It replaces the process of extruding the pipe with the Follow Me tool and grouping it thereafter, also allowing you to define an inner diameter as well.