C_CameraSolver
CaraVR's C_CameraSolver node creates an approximate camera geometry, relative to a nodal point or a sphere, for multi-camera rigs. This defines the location and orientation preview for each camera so that the images can be stitched by C_Stitcher for output.
Inputs and Controls
Connection Type |
Connection Name |
Function |
Input |
1 |
The sequence representing a camera on the rig you want to solve. When you connect the first input, a new input 2, 3, and so on is spawned, allowing you to connect multiple Reads. Warning: The Read nodes representing the cameras in the rig must be pre-sychronised, because CaraVR and Nuke do not support auto-synchronisation. |
Control (UI) |
Knob (Scripting) | Default Value | Description |
C_CameraSolver Tab |
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Local GPU |
gpuName |
N/A |
Displays the GPU used for rendering when Use GPU if available is enabled. Local GPU displays Not available when: • Use CPU is selected as the GPU device in the Preferences. • no suitable GPU was found on your system. • it was not possible to create a context for processing on the selected GPU, such as when there is not enough free memory available on the GPU. You can select a different GPU device, if available, by navigating to the Preferences and selecting an alternative from the GPU Device dropdown. Note: Selecting a different GPU requires you to restart Nuke before the change takes effect. |
Use GPU if available |
useGPUIfAvailable |
enabled |
When enabled, rendering occurs on the Local GPU specified, if available, rather than the CPU. Note: Enabling this option with no local GPU allows the script to run on the GPU whenever the script is opened on a machine that does have a GPU available.
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Input |
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Preset |
rigPreset |
Custom |
Sets the required preset rig information to load: • Custom - allows you to specify any number of cameras for the rig, with custom settings for each available in the Cameras tab. • PTGui - allows you to specify an existing rig created in PTGui. • Preset Rigs - select the required preset rig from the list to create the relevant rig with the correct number of cameras. These are rarely accurate enough to 'just work', but they provide a good basis for a solve in some cases. |
Setup Rig |
setupRig |
N/A |
Click to set up, or change to, the currently selected rig Preset. |
Cameras |
numCameras |
1 |
Displays the number of cameras in the preset rig or currently connected to the node in Custom rigs. |
Lens Type |
rigLensType |
Fisheye |
Sets the lens type used for all cameras in the rig: Rectilinear or Fisheye. If you're using both types of lens, use the controls on the Camera tab to customize the individual cameras. Note: This control is only available when Set global camera parameters is enabled. |
Set global camera parameters |
setCameras |
disabled |
Enable Set global camera parameters to activate the Lens Type, Sensor Size, and Focal Length controls. |
Sensor Size xy |
rigSensorSize |
36,24 |
Sets the sensor size used for all cameras in the rig. If you're using different types of sensor, use the controls on the Camera tab to customize the individual cameras. Note: This control is only available when Set global camera parameters is enabled. |
Film Back Preset |
rigFilmBackPreset |
Custom |
Sets the camera Sensor Size and Focal Length automatically for the preset selected. Note: This control is only available when Set global camera parameters is enabled. |
Focal Length |
rigFocalLength |
17 |
Sets the focal length used for all cameras in the rig. If you're using different focal lengths, use the controls on the Camera tab to customize the individual cameras. Note: This control is only available when Set global camera parameters is enabled. |
Keying |
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Analysis Keys
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Key number |
1 |
Displays the total number of analysis keyframes added to the sequence. |
Key count |
1 |
Displays the current analysis keyframe. |
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N/A |
N/A |
Click to jump to the previous keyframe. |
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N/A |
N/A |
Click to jump to the next keyframe. |
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N/A |
N/A |
Click to add a keyframe at the current frame in the sequence. |
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N/A |
N/A |
Click to delete the keyframe at the current frame in the sequence. |
Step |
keyStep |
500 |
Sets the interval between keyframes for the Key All button. |
Key All |
addAllAnalysisKeys |
N/A |
Click to add keyframes to the sequence at intervals set by the Step control. |
Delete All |
deleteAllAnalysisKeys |
N/A |
Click to delete all keyframes from the sequence. |
Import |
importAllKeys |
N/A |
Click to import existing keyframes automatically from C_CameraSolver, C_ColourMatcher, or C_Stitcher nodes in the current script. Note: Importing keyframes deletes any existing keyframes. |
Analysis |
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Focal Length |
focalLengthType |
Optimize Single |
Sets the focal length for the cameras in the rig: • KnownFocal Length - fixes the existing focal length in the solve. • Optimize per Camera - calculates the focal length for each camera in the rig. • Optimize Single - calculates a single optimized focal length for all cameras in the rig. |
Lens Distortion |
lensDistortionType |
No Lens Distortion |
Sets the lens distortion for the cameras in the rig: • No Lens Distortion - • Known Distortion - fixes the lens distortion in the solve. • Optimize per Camera - calculates the lens distortion for each camera in the rig. • Optimize Single - calculates a single optimized lens distortion for all cameras in the rig. |
Camera Layout |
layoutType |
Spherical Layout |
Sets thelayout for the cameras you intend to use: • Nodal Layout - all cameras are located at the scene origin and can't be adjusted. For example, a single DSLR shooting 360 stills would use this nodal layout setting. • Spherical Layout - the cameras in the rig are placed on a sphere whose diameter, defined by the Rig Size control on the Cameras tab, defaults to 30 cm. Tip: Setting the Rig Size control to the actual size of the rig in use allows you to enter real world measurements for other Cameras controls, such as Focal Length. Spherical layouts can be more accurate than nodal, and allow you to alter the Convergence between cameras to check for image alignment at different depths in the scene. |
Match |
matchCameras |
N/A |
Click to compare keyframes on overlapping cameras for shared features. Nuke only looks for matches in cameras that overlap by default. Note: Match calculates the feature matches for all cameras in the rig at the same time, so there is no need to calculate them separately for left and right images in a stereo setup. |
Solve |
solveCameras |
N/A |
Click to calculate the geometry for the selected rig to define the location and orientation of each camera, relative to the other cameras in the rig, and arrange the matched images in the correct order. Note: The Solve calculates the geometry for all cameras in the rig at the same time, so there is no need to calculate them separately for left and right images in a stereo setup. |
Refine |
refineCameras |
N/A |
Click to attempt to refine the camera solve using the current solve and feature matches. You might do this if you have rejected some of the automatic feature matches or if you have added some custom matches using the Add Match Viewer tools. |
Reject |
rejectMatches |
N/A |
Click to delete all current feature matches that fall outside the Error Threshold setting. |
Reset |
resetCameras |
N/A |
Click to reset the cameras in the rig to their default configuration. |
Solve Error |
solverRMSError |
0 |
Displays the root mean square (RMS) error for a solve. This is a good indicator of solve quality. |
Error Threshold |
maxRMSEThreshold |
10 |
Sets the solve error level permitted, below which feature matches are rejected. Reducing the allowed error level dynamically rejects features that fall out side the new level, allowing you to easily reject them and refine the solve. |
Output |
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Format |
outputFormat |
dependent on Compositing environment Project Settings |
Sets the output resolution passed down the node tree. Typically, you would set the format globally in the Project Settings, but this control overrides the global setting. |
Cam Projection |
cameraViewsProjectionType |
Default (pass-through) |
Sets the projection mode for the cameras output by C_CameraSolver: • Default (pass-through) - individual camera views are passed through in their native format. • Latlong - individual camera views are projected into latlong space, allowing you to make manual corrections before stitching. |
Converge |
convergenceDepth |
10 |
Sets the depth at which the cameras overlap, allowing you to bring particular areas in the scene into focus. The approximate diameter of the sphere on which the cameras sit uses the Rig Size control on the Cameras tab. This normalizes the 3D representation of the rig into close to real world units, depending on the quality of the solve. The Converge control then defines the depth at which the preview stitch is converged, the "hero" depth of the scene. Note: Convergence doesn't affect nodal rigs because all the cameras share the same origin. |
Cameras |
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Cameras |
camerasLink |
N/A |
Displays camera information for views connected to C_CameraSolver's inputs. As you match, solve, and refine the rig, the cameras in the table update with focal length and positional data. You can toggle cameras on and off to determine which cameras from the rig are displayed in the stitch preview. |
Export |
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Export Menu |
exportMenu |
Cameras |
Sets the export nodes to add to the Node Graph: • Cameras - creates Camera nodes, attached to an Axis and Scene, for each camera in the rig. • Transforms (split) - creates a single C_SphericalTransform containing rotation data for each camera in the rig. • Transforms (separate) - creates separate rotation data for each view using a OneView and C_SphericalTransform node for each camera in the rig. • Manual 2D Stitch - creates a RigWorkflow2D group containing a C_SphericalTransform for each view, passed into a JoinViews and C_Blender node to re-assemble the views into a coherent whole. • Manual 3D Stitch - creates a RigWorkflow3D group containing a C_SphericalTransform and Camera for each view, projected onto a Sphere and rendered through C_RayRender. • Ingest (joined) - creates ShuffleView nodes for all inputs, allowing you to assign inputs to views manually and then joins the views together. • Ingest (separate) - creates ShuffleView and OneView nodes for all inputs, allowing you to assign inputs to views manually. This export is similar to Ingest (joined), but the views are separated out into individual streams. • Contact Sheet - creates a ContactSheet containing all solved views for review purposes. |
Create |
exportButton |
N/A |
Click to create the export specified in the export dropdown. |
Camera Tab |
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Input Views |
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Left Views |
inputLeftViews |
left |
When Stereo is enabled, allows you to select which views to solve for the left eye. |
Right Views |
inputRightViews |
N/A |
When Stereo is enabled, allows you to select which views to solve for the right eye. |
Stereo |
stereoViewsInputSplitting |
disabled |
When enabled, select which views to solve for the left and right eye using the dropdowns. When disabled, solve all views. |
Rig |
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Cameras |
numCameras |
1 |
Displays the number of cameras in the rig. |
Rig Size |
rigSize |
0.30000001 |
Sets the diameter of the rig when Camera Layout is set to Spherical Layout. This normalizes the 3D representation of the rig into close to real world units, depending on the quality of the solve. The Converge control then defines the depth at which the preview stitch is converged, the "hero" depth of the scene. The Rig Size and Converge controls use the same units so if you set the Rig Size in meters, the Converge control also uses meters. |
Camera |
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Lens Type |
lensType |
N/A |
Sets the lens type used for the selected cameras in the Cameras table: Rectilinear or Fisheye. Note: This control is only available when you have a camera selected in the Cameras table. |
Sensor Size xy |
sensorSize |
N/A |
Sets the sensor size used for the selected cameras in the Cameras table. Note: This control is only available when you have a camera selected in the Cameras table. |
Focal Length |
focalLength |
N/A |
Sets the focal length (mm) for the selected cameras in the Cameras table. |
Position |
position |
N/A |
Sets the camera position in the rig for the selected cameras in the Cameras table, scaled to match the Rig Size setting. |
Rotation |
rotation |
N/A |
Sets the camera rotation for the selected cameras in the Cameras table for a ZXY rotation order. |
Centre Shift |
centreShift |
0, 0 |
Sets the center point shift for the lens of the selected cameras in the Cameras table. |
Distortion |
distortion |
0, 0, 0 |
Sets the distortion for the lens of the selected cameras in the Cameras table. |
Mask |
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Shape |
alphaShape |
Rectangular |
Sets the shape of the mask used to blend images from adjacent cameras: • Rectangular - overwrites the source alpha channel with a rectangular blend mask. • Elliptical - overwrites the source alpha channel with an elliptical blend mask. • Source - uses the source alpha as the blend mask. |
Size |
alphaSize |
N/A |
Sets the size of the blend mask on the x and y axis for Rectangular and Elliptical blend masks. Note: The Size control has no effect on Source alpha blend masks. |
Feather |
alphaFeather |
N/A |
Sets the feathering applied to the edges of the blend mask for Rectangular and Elliptical blend masks. Note: The Feather control has no effect on Source alpha blend masks. |
Links |
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Links |
links |
N/A |
Displays list of cameras linked to the selected cameras in the Cameras table. |
Output |
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View |
outputView |
All |
Sets the output view for the selected cameras in the Cameras table: • All - the selected cameras are used for both views. Use this option for monoscopic stitching or when you want to use the camera for both views in a stereoscopic stitch. • Left - the selected cameras are used for the left view in a stereoscopic stitch. • Right - the selected cameras are used for the right view in a stereoscopic stitch. C_CameraSolver outputs all cameras, regardless of your View settings. The View control adds metadata to the stream so that C_Stitcher can easily separate out designated cameras when Enable Stereo Stitch is enabled. In the Cameras table, the view column displays the camera's view: 0 (All), 1 (Left), or 2 (Right). |
Cameras |
cameras |
N/A |
Displays camera information for views connected to C_CameraSolver's inputs. As you match, solve, and refine the rig, the cameras in the table update with focal length and positional data. You can toggle cameras on and off to determine which cameras from the rig are displayed in the stitch preview. You can also select cameras to assign to different views in the stitch using the View dropdown. |
Set as Default |
setRigDefault |
N/A |
Click to set the currently selected camera as the rig default. Click Reset on the C_CameraSolver tab to revert this setting. |
Settings Tab |
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Matching |
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Match |
matchType |
Rectified |
Sets the matching method used when you click Match on the C_CameraSolver tab: • Input - analyze matches between the native source inputs. • Rectified - remove any lens distortion and then analyze matches between the source inputs. • Spherical - project the source inputs into latlong space and then analyze matches between the source inputs. Spherical matching is designed for rigs containing cameras with a field of view greater than 180°. |
Match in overlap region |
matchOverlap |
enabled |
When enabled, only match features in overlap regions between adjacent cameras. When disabled, match features across the entire image. |
User Matches Weight |
userMatchesWeight |
1 |
Controls how much influence user matches exert over the solve. The default value gives user matches far more weight than the automatic matches created by CaraVR. As you decrease the weight, bias moves toward the automatic matches. |
Solving |
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Solve for animated cameras |
animatedSolve |
disabled |
When enabled, calculate animated values for the camera parameters at each of the analysis key frames. |
Align horizontal camera ring |
correctHorizontalRig |
enabled |
When enabled, automatically correct cameras on spherical rigs so that cameras align horizontally. |
Display |
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Zoom Size |
zoomWindowSizePreset |
200px |
Sets the size of the zoom window in the Viewer. |
Magnification |
zoom Magnification |
x2 |
Sets the magnification in the zoom window in the Viewer. |
Transform |
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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 rig along the x, y, and z axes. You can also adjust translate values by clicking and dragging the axis in the 3D Viewer. |
rotate |
rotate |
0, 0, 0 |
Lets you rotate the rig around the x, y, and z axes. You can adjust rotate values by holding down Ctrl/Cmd and dragging in the 3D Viewer. |
uniform scale |
uniform_scale |
1 |
Lets you scale the rig simultaneously on the x, y, and z axes. |
Local matrix |
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specify matrix |
useMatrix |
disabled |
Enable this control to specify matrix values for the object 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 object’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. |
Python Tab (These controls are for Python callbacks and can be used to have Python functions automatically called when various events happen in Nuke.) |
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before render |
beforeRender |
none |
These functions run prior to starting rendering in execute(). If they throw an exception, the render aborts. |
before each frame |
beforeFrameRender |
none |
These functions run prior to starting rendering of each individual frame. If they throw an exception, the render aborts. |
after each frame |
afterFrameRender |
none |
These functions run after each frame is finished rendering. They are not called if the render aborts. If they throw an exception, the render aborts. |
after render |
afterRender |
none |
These functions run after rendering of all frames is finished. If they throw an error, the render aborts. |
render progress |
renderProgress |
none |
These functions run during rendering to determine progress or failure. |