How to bend objects correctly in Blender 2.8x


Assalamu’alaikum. Hi guys.

My name is Widhi Muttaqien from Expose Academy.

In this tutorial video, I want to show you how to use the new “bend” modifier feature that exists in Blender 2.8x which is part of the “simple deform” modifier. One of the most important things to know when using the bend feature is the correlation between the rotational axis and the working axis. Without this basic knowledge, you’ll get into trouble sooner or later when trying to bend objects in Blender.

In this tutorial, I also explain why you shouldn’t use the “limits” feature and how to work around it, which basically using an empty object and the vertex group feature.

I hope this short tutorial can be helpful. Happy Blending!

Video transcript:

Assalamualaikum. My name is Widhi Muttaqien from Expose Academy. In this tutorial video, I’m going to show you how to bend objects correctly in Blender 2.8 or above.

To bend object in Blender, you can use the bend modifier feature which is actually part of a general deformation modifier called the “simple deform” modifier. If you select an object and then add a “simple deform” modifier to that object. You can see “bend” appears here as one of the modes of this modifier. If you have been using Blender before version 2.8, you might already be accustomed to create an empty object to control the bend modifier. Well, I have good news for you. Since Blender 2.8, you don’t need to use any empty object anymore. Well, you can still use it for more control, which we’re going to discuss later. But out of the box, the bend modifier now allows you to pick the axis of the bending rotation. For example, let’s increase the angle here to 180 degrees so we can see the effect better. Previously we were stuck with only using the Z-axis, but now you can pick the Z-axis, or the X-axis, or the Y-axis. Now, although this looks easy enough. You still need to understand the basic concept of how this axis works to avoid you from confusion later.

To show you what I mean. Let’s delete this monkey head model. And let’s create a plane object. Go to the edit mode and subdivide it. And just max out this “number of cuts” value to 10. Now, let’s say you want to bend this plane this way using the X-axis. So you apply the “simple deform” modifier, and set it to bend mode. But, nothing happens. You can try changing the angle value. But still nothing. Then you might try changing the rotation axis to Y-axis. But still nothing. So what is going on here? Why the monkey head model bend so easily, while this plane object would not bend at all?

You see, the way the bend modifier works is like this. First, it will decide the rotational axis. Then it will define the working axis to determine the start and the endpoints. Then based on your angle value, it will bend and try to make the start and the endpoints meet together. So from this explanation, you need to know what is the working axis that Blender are using for that current rotational axis. If you do something like this. You add a lot of loop cuts but aligned to the wrong axis. Blender will still assume the working axis is this way so it still assume that the start and the end direction like this. You won’t get any bending effect due to the lack of edges in the working axis, which is supposed to be this way.

To save you some time experimenting with this by yourselves, here is the chart for the rotational axes and the working axes. Just remember this every time you use the bend modifier. So if you use the Z-axis for the bending or the rotational axis, the working axis is the X-axis. If you use the X-axis for the rotational axis, the working axis is the Z-axis. And finally, if you use the Y-axis for the rotational axis, the working axis is also the Z-axis. So, if we go back to our plane example here. If you want to bend it correctly using the X-axis. You need to align the cuts to the correct working axis which is the Z-axis direction. To fix it. Go to the edit mode. Select all. Press R, X and then type 90. Then Enter. Now, we can see the object bends as we expected.

Next, I want to discuss these “limits” values. Remember my explanation about the start and the endpoint? Essentially “limits” values will move the start and the endpoint to any location you like along the working axis. This can be a good tool if it works. But most of the time, I find this “limits” values useless because they will cause the object mesh to rotate like crazy. To show you what mean. Let’s say you want to create a street lamp pole. So it is straight like this from the ground and then when it almost reaches the top it bends like this. Later you can model and add the lamp housing here. Okay. So we can start by creating a cylinder. Let’s reduce the vertices to only 12. Go to the edit mode. We want the origin to be exactly at the bottom part of this cylinder. To do that, we can just move this up by pressing G, then Z and while moving it, hold the Ctrl key modifier until it snaps like this. Press S and then Shift Z to make the diameter smaller. Then select the upper face here. Move it up, way up, about this high. Make it smaller. Then Ctrl+R, left-click and right-click. And just change the “number of cuts” value here to 40 for example. Next, go back to the object mode. And add a “simple deform” modifier. Make sure it is set to “bend” mode. Now if we set the angle to 180 degrees, we get something like this. Imagine this is the start point and this is the endpoint. Notice as I increase the start point percentage, part of the pole becomes stiff. It is doing it because the bend modifier skips bending the starting part of the pole. As we can see, it is hard to work with these “limits” values, because the resulting mesh is rotated. You can apply the modifier and fix the rotation later afterward, but that will be just unnecessary additional works.

So to approach this lamp pole modeling problem. We’re going to use the rest of the bend modifier features that we haven’t discussed yet, and that is by using an “empty object” and the “vertex group” feature. So go to the edit mode. Turn off the modifier preview in the edit mode so we can see the original mesh. Select the face up here. Press Ctrl + Numpad plus several times so half of the upper mesh is selected. Go to the Data tab. Create a new vertex group. And assign the existing selection to that group. Next, go back to the object mode. And open the modifier panel. Pick the vertex group we created before from this list here. Now it looks ugly. But we’ll fix this soon. Next, create an empty object, I prefer the arrows type as we can see the axes. Move it up. You can use snapping for this, but I’ll just eyeball it for now. Next, from the axis origin option choose the empty object. And we have something like this. I think we need to increase the angle value to around 220 will do great. And there you have it. A street lamp pole made using the bend modifier. You can continue modeling the lamp housing from this point, if you want to.

Okay guys. If you want to learn more about computer graphics. Perhaps you want to jump into the video game industry. Or perhaps you want to create digital assets that can generate passive income. Or you want to have a career doing something you really love. Or become an entrepreneur in the creative industry and build your own design firm. Or maybe you just want to learn CG as a hobby. Then you should check out my courses at Udemy or at Skillshare. The links are in the description below. Currently, I have courses in Blender, 3ds max, Photoshop, Adobe Illustrator, and Krita. And more to come -in sha Allah-. All of these courses will guide you from the very basic, step by step, until you can master the skills that you need. As always, subscribe to my channel. Share the video. Give a thumbs up if you like the video, and give a thumbs down if you hate the video. Check out my other tutorials. Wassalamualaikum.