The mesh operations stack

- [Instructor] This video is going to be an introduction to the Mesh Operations Stack in Modo. So in Modo, procedural modeling is carried out by means of mesh operations, or MeshOps, for short. And these are organized in a special view port, which you can open by clicking on this icon here, if you're in the Modo layout. And in the MeshOps view port, your mesh operations are organized in a stack, working from bottom to top. So, let's create a procedural model. I'm going to click on Add Operator, I'm going to make sure I'm in the Create section and I'm going to double click on the cylinder to add a cylinder MeshOps to my stack. And once these cylinder MeshOps has been added, I can interact with the handles that are drawn in the view port in order to change the dimensions, or I can set values numerically here in the Properties panel. And as long as you're in Item mode, that is to say you're not in one of the component modes up here, you can also use the Channel Haul tool to adjust the values. Let me show you how that works. For example, let's say I want to adjust the X and Z values proportionally. That is to say, I want to adjust them together. Well what I need to do is to click on the X channel to select it and then hold the control key and then click on the Z channel to also select it, and then I hover over the view port and hit the C key to activate the Channel Haul tool. And now I can left click and drag in my view port to adjust both those channels together. And while the Channel Haul is still active, I can then click on the Y channel to select that on its own and now when I click and drag in the view port, you can see I'm adjusting the Y dimension. Once I finished, I can hit the Q key to drop the Channel Haul tool and I'm back to the normal handles. So now just drag this tool handle to sit the bottom end of my cylinder at the origin, and I'll just increase the number of segments in my cylinder to 10, and I'll change the polygon type from Face to Catmull-Clark, and I'll also make sure that neither the top nor the bottom are capped. And with the caps removed, you can see that we now have a completely hollow cylinder. So now I'm going to add some thickness to the cylinder. I'll go to Add Operator, go to the polygon section, and double click on the Thicken Mesh operator. And once again I can either interact with the handles that are drawn in the GL view port, or with the numerical values that are displayed in the properties form. And now let's add another operator on top of the Thicken. I'm going to click on Add Operator and this time, rather than browsing for it, I'm going to search up here in the search field. I'm going to type push, and then I'll double click on the Push operator. And I'll grab the handle that's in the OpenGL view port and I'll just drag to increase the push value on my mesh. So now I want to talk about the order of operations. As I said at the start of the video, the MeshOp stack works from bottom to top. So each mesh operation is evaluated one after the other, and the order that they are organized in is important. So for example, if I was to select the Thicken operation and drag it above the Push operation in the stack, you can see that changes the final result. And that's because the Thicken is now being applied after the Push operation rather than before it. So the order of operations of your stack is very important. Now in this Mesh Operations view port, you also have some options that allow you to visualize both the current state of the mesh and the final state of the mesh. Let me demonstrate. I'm going to select the first operation in the stack, and then I'm going to click on this Ghosted View button here at the top of the Mesh Operations view port. And so with the ghosted view active, what you see in gray is the current state of the mesh, where the cylinder's being created, and what you see in blue is the final state of the mesh. And so the ghosted view will update dynamically as I move up and down the Mesh Operation stack. So with Ghosted View off, I'm always looking at the final result, no matter which mesh operation I have selected. But with Ghosted View on, I have a much clearer idea of what the current state of the mesh is whenever I have a specific mesh operation selected. You also have the option to hide the final result if you wish, and that will simply terminate the stack at the currently selected mesh operation. So with this introduction out of the way, you should know have a clearer understanding of the Mesh Operator's panel and the importance of the order of operations within it.