Camera

Cameras may be connected to either the Scene node or the ScanlineRender node. Camera connected to a ScanlineRender node define the projection for use by the 3D renderer. You can connect additional cameras to the Scene node and switch between them by choosing the viewing camera from the dropdown menu at the top of the Viewer. You can also read in .fbx and .abc scene files containing standard cameras, though only one camera per Camera node can be read.

Cameras can also be used to project 2D textures onto 3D objects in a scene using the controls on the Projection tab and a Project3D node.

Inputs and Controls

Connection Type

Connection Name

Function

Input

axis

An optional Axis node input. This links the position, rotation, scale, and skew of the transformed 3D object(s) to the Axis node, so that the transformation controls on the Axis node override the corresponding controls on the TransformGeo node.

If you’ve worked with other 3D applications, you may know the Axis node as a “null” or “locator” object.

look

An optional input where you can connect a Camera, Light, or Axis that the Light is automatically rotated to point toward. The Light is automatically rotated to point towards the connected input whenever the look input is moved.

Control (UI)

Knob (Scripting)

Default Value

Function

Camera Tab

read from file

read_from_file

disabled

When disabled, the camera is configured using the controls on the Camera tab. Enable read from file if you want to read in camera information from an .fbx file using the File tab.

Note:  This control is linked to the read from file control on the File tab.

display

display

wireframe

Adjust the display characteristics of the camera. These settings don’t affect the render output of the scene; these are for display purposes only in the 3D Viewer.

• off - doesn't display the camera geometry.

• wireframe - displays only the outlines of the camera geometry.

• solid - displays the camera geometry with a solid color.

• solid + lines - displays the camera geometry as solid color with the camera’s geometry outlines.

• textured - displays only the surface texture.

• textured + lines - displays the wireframe plus the surface texture.

selectable

selectable

enabled

When enabled, you can make selections as normal in the Viewer. When disabled, points cannot be selected or changed.

file_menu

N/A

Select to import or export a channel file:

• Import chan file - import a channel file and transform the camera according to the transformation data in the channel file. Channel files contain a set of Cartesian coordinates for every frame of animation in a given shot. You can create and export them using Nuke or 3D tracking software, such as 3D-Equalizer, Maya, or Boujou.

• Export chan file - export the translation parameters that you’ve applied to the camera as a channel file. This is a useful method of sharing setups between artists.

snap_menu

N/A

• Match selection position - the camera is snapped to a new position depending on the points selected.

• Match selection position, orientation - the camera is snapped to a new position and orientation depending on the points selected.

• Match selection position, orientation, size - the camera is snapped to a new position, orientation, and size depending on the points selected.

transform order

xform_order

SRT

Sets the operation order for scale (S), rotation (R), and translation (T). The possible operation combinations are SRT, STR, RST, RTS, TSR, TRS.

rotation order

rot_order

ZXY

Sets the order of rotation. The possible axial combinations are ZXY, XYZ, XZY, YXZ, YZX, ZXY, ZYX.

translate

translate

0, 0, 0

Lets you translate the camera along the x, y, and z axes. You can also adjust translate values by clicking and dragging the camera in the 3D Viewer.

rotate

rotate

0, 0, 0

Lets you rotate the camera around the x, y, and z axes. You can adjust rotate values by holding down Ctrl/Cmd and dragging in the 3D Viewer.

scale

scaling

1, 1, 1

Lets you scale the camera on the x, y, and z axes.

uniform scale

uniform_scale

1

Lets you scale the camera simultaneously on the x, y, and z axes.

skew

skew

0, 0, 0

Lets you skew the camera on the x, y, and z axes.

pivot

pivot

0, 0, 0

When you make changes to a camera’s position, scaling, skewing, and rotation, these occur from the location of the camera’s origin point or pivot. The pivot x, y, and z controls allow you to offset the pivot point and move it anywhere you like - you can even move it outside of the object. Subsequent transformations applied will then occur relative to the new pivot point location.

You can also hold down Ctrl/Cmd+Alt and drag the pivot point to a new location in the 3D Viewer.

Local Matrix

specify matrix

useMatrix

N/A

Enable this control to specify matrix values for the camera you’re transforming as an alternative to setting transform, scale, skew and pivot values above.

matrix

matrix

N/A

The matrix displays values from the camera’s transform, rotate, scale, skew, and pivot controls.

Check specify matrix and copy or drag-and-drop matrix values from another object to apply those values, for example, if you wanted to align objects in a scene.

World Matrix

World matrix

world_matrix

N/A

Displays the world or absolute xyz transform of the node in world coordinates.

Note:  Unlike the Local matrix, you can’t adjust the World matrix manually.

Projection Tab

projection

project_mode

perspective

Sets the camera projection type when projecting 2D textures:

• perspective - objects in front of the camera have the illusion of depth defined by the camera's focal-length and aperture.

• orthographic - objects are viewed using parallel projection.

• uv - every object renders its UV space into the output format. Use this to cook out texture maps.

• spherical - the entire 360° world is rendered as a spherical map.

focal length

focal

50

Adjusts the camera’s level of magnification.

horiz aperture

haperture

24.576

Sets the horizontal aperture of the camera.

vert aperture

vaperture

18.672

Sets the vertical aperture of the camera.

near

near

0.1

Adjusts the position of the camera’s forward clipping plane. Objects closer to the camera than this plane are not rendered.

Note:  The value for the near clipping plane must always be positive to produce a sensible result.

far

far

10000

Adjusts the position of the camera’s rearward clipping plane. Objects farther from the camera than this plane are not rendered.

window translate uv

win_translate

0, 0

Translates the camera’s output along the uv axes.

window scale uv

win_scale

1, 1

Scales the camera’s output along the uv axes.

window roll

winroll

0

Rotates the camera’s output around the z axis.

focal distance

focal_point

2

Controls the distance from the lens where the camera focuses.

fstop

fstop

16

Sets the f-stop value (relative aperture) of the camera.

File Tab

read from file

read_from_file

disabled

When disabled, the camera is configured using the controls on the Camera tab. Enable read from file if you want to read in camera information from an .fbx or .abc file using the File tab.

Note:  This control is linked to the read from file control on the Camera tab.

file

file

N/A

Sets the file path for the .fbx or .abc file from which you intend to import camera information.

reload

reload

N/A

Click to reload the camera information from the specified file.

USD Options

scene_graph

N/A

When the file path is pointing to a valid .usd file, the USD Options are displayed.

The USD Options show a scenegraph containing a list of the item names and their paths inside the .usd file.

Click an item to select it and load it into the scene. The selected item can be identified in the Load column.

Items in the .usd file that weren't originally loaded can still be viewed in scenegraph and loaded into the scene.

Note:  For more information about importing Cameras from a .usd file, see Importing USD Items.

animation stack name

fbx_take_name

N/A

When the file control is pointing to a valid .fbx or .abc file, select the required take name from the dropdown menu.

node name

fbx_node_name

N/A

When the file control is pointing to a valid .fbx or .abc file, select the required node name from the dropdown menu.

frame rate

frame_rate

24

When use frame rate is enabled, enter the required frame rate to use instead of the rate specified in the input file.

use frame rate

use_frame_rate

disabled

When enabled, the frame rate from the input file is ignored and the specified frame rate is used instead.

compute rotation

compute_rotation

disabled

When enabled, compute the camera rotation values using the look up vector and look at position. The rotation values are always computed when there is a look at target.

Look Tab

look axis

look_axis

-Z

The axis around which the Camera is rotated to face the look input.

rotate X

look_rotate_x

enabled

Determines whether the rotation occurs around the X axis. Note that for the rotation to truly "look at" the look input, all three of these options must be activated.

rotate Y

look_rotate_y

enabled

Determines whether the rotation occurs around the Y axis. Note that for the rotation to truly "look at" the look input, you have to set all three of these options.

rotate Z

look_rotate_z

enabled

Determines whether the rotation occurs around the Z axis. Note that for the rotation to truly "look at" the look input, you have to set all three of these options.

look strength

look_strength

1

Determines to what extent the Camera rotates to the new orientation. The smaller the value, the less the object is rotated. Setting the value to 0 produces no rotation.

use quaternions

look_use_quaternions

disabled

Uses an alternate scheme to calculate the look rotation. This option may be useful to smooth out erratic rotations along the look axis.

Step-by-Step Guides

Working with Cameras

Video Tutorials

3D Workspace Overview from Foundry on Vimeo.

Nuke is not limited to a 2D space, in fact, it has a complete 3D environment built right in. For example, here is a 3D ship and a 3D sphere. In order to see the 3D environment, go to the View menu where it says 2D and switch that to 3D, and there’s the environment. In order to change the view, which is the default camera, you can use the Alt or your Option key, along with your mouse buttons. For example, Alt and left mouse button scrolls, Alt and middle mouse button zooms, and Alt and right mouse button orbits.

Let’s see what we have in the scene. There is a 3D Camera, a Spotlight, a Point light, a primitive Sphere, an imported spaceship, and a large primitive Card in the background. Let’s take a look at the node network, and you can see what we need to make a 3D scene happen. The node with the most connections is the Scene node. The Scene node groups together lights and geometry in order to pass them on to a render node. In order to render the scene so it becomes 2D, you need to have some sort of render node. In this case, there is a ScanlineRender node. Connected to the ScanlineRender is a 3D Camera. Connected to the Scene node are two lights - there is the Spotlight and the Point light. If I open up the properties on the Spotlight, you can see common options like color and intensity and, in the case of the Spotlight, cone angle. There are also two pieces of primitive geometry here - there is the Sphere and the Card. This will be a good time to note that 3D nodes have a rounded, pill-like shape, as opposed to the rectangular 2D nodes.

You can create a light or a primitive piece of geometry through the 3D menu. You can make your Point or your Spot, plus a Direct and a few specialized lights, like the one that’s called Light, which you can use to import lights from other programs, like Maya. There is also the Geometry menu, which has the primitives such as Card, or other shapes, like Cube and Cylinder. You can transform lights and geometry. For example, if I open up the Sphere, you will see there is a translate, rotate, and scale property. Once this is open, you will also see there is a transform handle. If you click+drag the handle along the axis, you can move it in that direction, for example, Y. Of course, you can also enter values into the properties panel. Lights also have their own set of transforms. Now, one new feature is the fact that lights can cast shadows right here in the 3D environment. For example, if I go to the Spotlight and go to the Shadows tab, you will see there is a place to click on cast shadows. Let’s go back to the 2D view. You can see the shadow of the Sphere right here on the spaceship. Now, aside from shadows of course, you can animate all of these properties. You can animate the light, changing over time, as well as the geometry. There are also animation buttons beside all of these properties. You can key these as you would any other node inside Nuke.

You will notice that the two pieces of geometry have shaders connected to their img pipes. These are necessary for the surfaces to be lit correctly. The Sphere has a Phong, which is similar to the one you might have in a program like Maya. The Card has an Emission shader, which has the emissive component or the ambient color component. Now, in terms of the spaceship, it has to be imported through a ReadGeo node. ReadGeo node has a place to bring in the file, and this supports .fbx files, or .obj files, or alembic files, .abc. If there is animation in the file, Nuke will recognize it. For example, with the .fbx file, it might have multiple takes. Nuke will recognize that and you can choose the animation take. So, if I go back to the 3D view, scrub the timeline, and we will see the ship is pre-animated, and this animation was created in Maya. There is also a material connected to the img pipe of the ReadGeo. Now, because the UV texture space came through the .fbx file, in order to map the geometry, you just need to bring in the texture bitmaps through Read nodes, and connect to a shader. For example, here is the diffuse map connected through the mapD, or map diffuse. There is a specular map connected through the mapS, or map specular. Lets go back to the 2D view.

Now, if anything is animated, you can also activate motion blur. To do that, you go to the render node and, for example, with the ScanlineRender, go to the MultiSample tab and change samples to a higher number like 8. At that point, the motion blur will appear, as you can see right here. The higher the samples number, the higher the quality.

So, there is a brief introduction to Nuke’s 3D environment. Keep in mind that any node you need to create for this you can find through the 3D node menu. This includes all your shaders, geometry, lights, Scene nodes, and cameras. Aside from animating lights and geometry, you are also free to animate cameras. They have their own set of transforms. In any case, I would suggest exploring this component of Nuke.