From the course: Houdini Essential Training

Cameras - Houdini Tutorial

From the course: Houdini Essential Training

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Cameras

- [Instructor] Now we're going to take a look at how we can create cameras in our scene in Houdini. So far in this course we've been using cameras that I've provided for you in these scenes, and now I'm going to show you how you can make your own. There's a few different places we can create cameras from, and we'll start with the first most basic one, which is just creating it from the shelf. On the upper part of our screen, we've got our shelf on the right here which is the Lights and Camera shelf, we're just going to grab the camera, click that and lay it down in the scene. All right, so now I've got a camera and we've got some manipulators coming off of it. The way we select cameras in our scenes is via this uppermost dropdown menu in the right upper corner of our View port, and you can see that there's a few options in here and here are the cameras in my scene. The RENDER and TEST cameras are cameras I've provided, and then this cam1 is this new camera we just made. I'll select that, and you can see down here in our Network View, that is that camera that got created. Now in order to make sure as we manipulate around in this scene that we're actually moving the camera, what I need to do is I need to hit this lock button right here, and as I hit that lock button, you can see that now we have a lock next to that cam1. Now I'm going to hit the Escape key, and look down here over on the left side of this column of icons, and I hit the Escape key, we go into the View Tool mode, which means that we're manipulating cameras. Now I can use my mouse buttons, I'm going to scroll out, and I'm going to just kind of move around. You can see right now in our Network View, because that cam1 is selected, as I move my camera around, the Translate and Rotation parameters are following suit with that camera. Here I've framed up a new camera in my scene. OK, so let me just move this over a little bit to get us some more screen real estate. I'm just going to show you the two other ways we can make a camera. Second way would be from this dropdown menu itself, I could just say New Camera. Now you see we have cam2 down here, and we have cam2 there, and with this lock still selected, we don't need to do anything else to keep manipulating it. We're still in View Tool mode, as we can see over here. Now I'm just going to manipulate around and let's just get another view of our scene. All right, OK, cool. Now I can switch between my two new cameras just by switching between them on the dropdown menu. The third way I'm going to show you how to make a camera is simply quite from the Network View. I could go to my Network View and hit Tab as we do to get our little node menu, and I'm going to type C-A-M, and you can see there's a bunch of different kind of cameras we can make, VR Camera and some Stereo Cameras and things when you're doing more advanced work. But we're just doing a basic camera right now, so I'm going to lay that down. You can see this is automatically called cam3, and then it's all zeroed out. None of these cameras are any different even though we made them in three different parts of Houdini, they're all the same camera, they're just three different ways to make them. Now I could select our new cam3, it automatically gets populated in this list. Our lock is still down, we're still in View Tool mode, so now I will just do a little third frame up here. OK, cool, so now we have three cameras we've made in three different ways in Houdini, and we've seen how to look through them. The cameras have a bunch of different settings, and I'm going to show you where we set the primary ones, which are resolution and focal length. We're looking through camera 1 here, I'm going to select that. Under the View tab here, you can see we have a lot of different parameters and we're going to focus on the main ones which are Resolution and Focal Length. Here we have a, by default, 1280 by 720, so HD frame size frame. This is totally arbitrary, we can make this anything we want. Then this can be passed to the renderer to render it this size, or in our render nodes, we can manipulate the size if we want to render something larger or smaller. Let's say I wanted this to be 1280 by 200. You can see that now it is this long thin aspect ratio, and everything outside of that is grayed out a bit, and now we have a camera view of that size. It's that simple just to change our camera resolutions. If we click this dropdown menu here, too, you can see that we have defaults for all the primary camera resolutions that you'd use in traditional production. OK, the other important thing here is Focal Length. Starting out with a default 50 millimeter lens, let's say I wanted to make it a little bit more wide angle, so let's say I make it 28, there we go. That's how we change our focal length. I'll make it 35 for the moment. OK, here we can also set our Clipping planes for all the various purposes, set our Z depth, so on and so forth. Here we can set a Background Image if we want to have a reference image in the background as well. The final tab I'm going to show you is this Sampling tab here. If we were dealing with motion blur and depth of field, here is where we can deal with our Shutter Time, Focal Distance and F-Stop for our cameras. The one last thing I want to show you here is that you can see how the cameras that I had provided, already we have just this TEST_CAM, and let's look through that. That, let me select it, you can see that I had just set that sort of manually in this scene like we had done before, and that it also locked those parameters. We haven't looked at that before, and I'll just show you this real quick. If I right-click over a parameter here, you can see there's this Unlock Parameter option. If I right-click again, there's this Lock Parameter option. You can do that all over Houdini, and I've just done that so that the camera that I provided for you wouldn't get moved from the position that I set. One other really important thing I want to show you here is the fact that with the RENDER_CAM I've provided, which is sort of just the front scene view, the RENDER_CAM itself has its Translates, Rotates, Pivots, all of that has been zeroed out and has been locked. It's actually all been controlled by a null above it where those Translates and Rotates have been applied. When we're doing production in a serious way, we're often using complex or even just minimally complex camera rigs where we're not actually animating a camera itself, but we're animating a series of nulls or all sorts of other things then propagate down to the camera's motion. That's very easy and straightforward to set up in Houdini. Right here I just have a null that's just wired into this RENDER_CAM. For example, if I go back to our camera 1 here, I'm going to hit Tab > N-U-L to make a null, all I need to do is just wire that null into this camera. I'm going to leave the camera settings in this camera as we had set them before. Let me look at the Translates and Rotates. I'm just going to leave them as that. I'm going to select this null, and I'm going to middle mouse click over the Translate to get my value ladder, and I'm just going to scroll up and down. Now you can see that we are keeping the same camera position and rotation, but now we're affecting that via this null that's fed into that. This is just kind of doing a vertical lift rig on this camera. Very simple example, but as you can see, it's very easy to build some really interesting and useful rigs in Houdini, by just, for example, wiring a few different nulls together as you often maybe want to separate your Translations from your Rotations to be able to do more intricate controlled camera work. All right, so that's how we make and set up and manipulate cameras in Houdini as well as a little inkling of how we start to build camera rigs.

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