In this tutorial we will be covering something that can cause more than a headache while working in an isometric perspective: circles. Not only we'll take care of the top and side views, we'll also be taking this to the next level and create some cylinders too. First of all, we need to have an isometric grid. There are a lot of resources and tutorials on how to do this, I'll explain you my method. Create a New file. For now, enter the same specifications in Width and Height as seen below. This will help in the next step. Then, double click on the Line Segment Tool (). Create a line that has the below settings. While the 'true' isometric projection uses a 30º angle, we're going to change it up a bit, using a 26.565º angle. Here's why: most of the isometric graphics we see today use a variant of the isometric projection called '2:1'. This was born in the days of pixel art and it's still used today, as a 30º may result too steep from an aesthetic point of view. Now, align that line vertically with the canvas (by hand or using the Align panel - you don't need to be precise at this time) and move it outside the artboard. Drag that line using the Selection Tool (V) and while doing that, press and hold Alt + Shift to duplicate and keep the movement perfectly steady. Now that we've got one line on each end of the artboard, we can start creating our grid. Select both lines with the Selection Tool (V) and go to Object >, Blend >, Make. In the Spacing field, select Specified Steps and enter a number no minor than 30. This will determine how big or small the modules on your grid are going to be. After that, select the result and create a duplicate on top of it. You can do this by Copying and Pasting in Front (Ctrl + C, then Ctrl + F). Select the duplicate and flip it horizontally by going to Object >, Transform >, Reflect. Make sure you select the Vertical Axis. Now that we have everything ready, let's start! First of all, let's Create New Layer called 'Artwork'. Then, we're going to turn Smart Guides on by pressing Ctrl + U or going to View >, Smart Guides. The good thing of having Smart Guides on, is that you can use the Pen Tool (P) to draw shapes that are perfectly in grid. Here's the crucial step: duplicate the cube so you won't lose it, select one face of the new cube and go to Effects >, Stylize >, Round Corners. Now, enter the highest possible value and click OK. Once you're done with that, repeat with all 3 sides of the cube. Then, select them all and go to Object >, Expand Appearance. Now that we have those, we can create rounded shapes in isometric view, such as cylinders. But before we do that, there's a little tweaking that we have to do in the top circle: Select the Add Anchor Point Tool (+) under the Pen Tool (P) sub-menu and add new points on the four extremes of the path (aka where there is a little straight line). Do not erase any anchor point. Now, have those 3 circles away from the artboard and always duplicate them before using them. Same thing goes for the cube. It's very helpful to have a copy available. To make a cylinder, all we need to do is to take the top circle, cut the horizontal extremes, separate them vertically and re-join the anchor points using Object >, Path >, Join (Ctrl + J). Finally, you can use another circle and put it on top to give the illusion of a border Now that you know how to create isometric circles, you can experiment and create all kinds of shapes. There's basically no limit to what you can create now that you can do both straight and curve shapes! Envato Tuts+ tutorials are translated into other languages by our community members—you can be involved too! Source.