Understanding 3D - Concepts and Principals
I have 10 different things that I want to talk to you guys about so that when we are working in Photoshop, you can see what these things are. The first thing that I do want to mention is if you're working with Photoshop CC, and you do not see the 3D menu button right up here...this guy there, 3D, it may be because you don't have a 64-bit platform or your computer has less than 512 megabytes of video RAM. If you don't know how much video RAM your computer has, you can press CMD+K. That's CTRL+K on Windows. Go into 3D, and you'll see the total available RAM. So this particular laptop that I have here has one gigabyte of RAM, so double than what is required. So ideally, you want to be over 512, and if you're under it, you simply won't see the 3D menu, so you would need a need better computer. So that's the one thing I wanted to mention before we actually got started with the slides here. So the first... Actually, that's not a good idea. So the first thing I want to talk about is the X, Y,...
and Z coordinates. When we're working with 2D images, we have two coordinates. The Y coordinate that goes up and down and the X-axis. It goes left and right. If you open your info panel and you hover over your canvas, you can see here the X and Y coordinates. There they are, right there. Notice that as I hover over it, you'll see the coordinates right there. And the numbers there, the values that you see there correspond to whatever the unit of measurement that you have in Photoshop at the time. So if you press CMD+R, CTRL+R and right-click, you can select Inches, which is currently selected. But I can switch to Pixels, and now, when I hover over the Info panel, you'll see the X and Y coordinates. When we're working with 3D, we add a third coordinate, which is the Z coordinate. And that one interprets depth, so we have X, Y, and Z. So we're going to be dealing a lot with those three axes in 3D. We're going to be working with 3D meshes. That is the wireframe that creates the 3D model, and the 3D meshes are created from thousands or millions of polygons. Polygons are those tiny little triangles you see there. So a good way of relating polygons to something that might be familiar to you is to pixels. A bunch of pixels make up an image. Same thing with polygons. So polygons put together make up the 3D model. Photoshop's primary method of creating a 3D model is by extrusions. Essentially, you have a 2D shape, and you extrude it out in 3D space. And a good way of describing it is as pushing Play-Doh through a dough cutter. So when you push it, you get a 3D version of whatever that stencil shape was. So that's essentially what Photoshop does in 3D. It pushes things out into 3D space. And then we have materials. Materials is what gives the appearance to the 3D object's 3D surface. And that could be the texture or valiant meaning, for example, in this case, the hat has bitmaps, which are the illusion of detail. You're not really modeling the detail. You're just faking it, so that's what a material is. It allows you to put different textures together so that you can fake the detail in the look onto the 3D model. And Photoshop comes with 36 material presets, and that is done through a process called UV texturing or UV textures. Essentially, the 2D image, that checkerboard, wraps around that hat. That would be an example of how a 2D image wraps around a 3D model. And the reason that it's called a UV texture is because we're using the U and the V coordinates. And so instead of X and Y, we're using U and V. So it's the same difference. It's just a different way of saying the same thing. Then we have the ground plane. The ground plane is a 3D element that Photoshop automatically generates where the 3D object sits. It can catch shadows and reflections. That grid will not print or it will not save onto your final image. You can think of it as a guide. In Photoshop, we use guides to align things. The grid works the same way with the added benefit that it does catch shadows and reflections if you want it to. Then we have the camera. The camera is essentially your canvas. Whatever you're looking at through the canvas. that is the camera, and that's what will be saved in the final output. You can move the camera around your 3D model, and you can think of it as you, yourself, moving around the 3D model, not the 3D model moving. You can move the 3D model, of course, but you can move around it so you can look at it from different angles. So in the example here, I save the same hat in the same spot, but I just saved it from two different camera point of views, so that's how I got the two different renders. Then we have a scene. A scene is simply a 3D layer, and you will recognize 3D layers because they have a little cube on the bottom right of the layer thumbnail. And essentially, a scene contains all your 3D elements, essentially, everything we just talked about. And finally, rendering. Rendering is the process of Photoshop calculating all the textures, lights, and any other materials that we have applied to that 3D object so that we can get a final image. So when we're working in Photoshop, we can see a preview, but it won't be the same as the final result because Photoshop hasn't had the time to calculate light reflections and all those things that I just talked about. So those are the 10 things that I wanted to mention before we get started, and I also want to talk about the workflow in Photoshop. Generally speaking, of course, you can mix and match here. But generally speaking, the 3D workflow is like this. You start with a 3D model either by creating it or importing it. Then you apply a material that is to give it the look, the visual properties of the surface. Then you apply lighting to it, so that could be also shadows and reflections. And then you render it, meaning you let Photoshop calculate all those settings into the final image, and then you can use Photoshop to apply traditional enhancement filters or adjustment layers and things like that just to make the image look better than the actual render.