iRacing – iRacing Camera Tool

iRacing Camera Tool

Introduction

This is a brief introduction to the new camera tool built into the iRacing simulator. You can enter the
camera tool when in replay mode by hitting Ctrl-F12 at any time, hitting escape will exit the tool. Here
is a screenshot of the tool in action.

The camera system is broken down into four basic parts: Positioning the camera, aiming the camera,
setting the lens up and selecting the active camera for a given moment in time. Let’s break them down
one by one.

Positioning the camera with Position Type

There are four ways in which the cameras can be positioned. Statically placed in a fixed spot along the
track, positioned relative to the center of the focus car, positioned relative to the car but not fixed to
the chassis of the car (the chase and chopper cameras fit this description), or fixed on an independent
motion like with the blimp camera. Let’s break each one down in turn.

Fixed – fixed cameras are statically placed in the world, they do not move from frame to frame. Offset
sets the position and height of the camera in meters, relative to some arbitrary point near the center of
the track

Blimp – A blimp camera does a circle around the track, by default it centers itself over the track and
sets its radius to be just smaller than the widest part of the track. Offset sets the center of the radius
and the height of the blimp from the ground. The Blimp radius sets the size of the circle the blimp will
travel. And finally Blimp velocity sets the speed of the blimp in meters/second. The blimps position is a
function of radius/speed/ and the current time since the simulator started.

Chopper – The chopper camera is dragged behind the car, using a spring/damper mechanism to allow
it to wander a bit off course. Position sets the target height and distance from the car, but the Y axis is
completely ignored, and the X axis is fixed to always be a negative offset. The chopper will try to
maintain the requested distance and height but will drift from the target as the speed and direction of
the target car changes.

Chase – A chase camera orients itself a fixed distance (using the offset vector) from the focus car. But
it is oriented relative to the direction of travel of the focus car (not the direction the chassis is aiming),
and it is locked to a fixed height above the track surface. The chase camera can be set to any angle
relative to the focus car, and any height above the track surface. In addition this camera forces the lens
to always aim at a fixed point above the track, close to the center of the focus car. This allows the
camera to visualize the vertical motion of the car since the track will remain stationary as the car
bounces up and down.

OnCar – The on car cameras are fixed to the frame of the car, in the same way the static cameras are
fixed to the track. As the car moves, the on car cameras move in perfect step with the car. Position is
relative to the center of the car, so a position of {0,0,0} is the center of the car. Oncar cameras force the
aiming to be static relative to the chassis. This has to be the case since the camera is attached to the
focus car and all other aiming styles require a focus car to aim at.

Aiming the camera with Aim Type

There are three aiming modes for the camera. Aim statically in a fixed direction, aim at a focus car, and
aim at a group of cars. In addition dampening can be turned on to add in some error to the positioning
and make things appear more natural, like a human operator is controlling the camera. Let’s break each
type down in detail.

Static – Static aiming aims the camera in a fixed direction using the orient vector. This vector is made
up of Yaw (side to side), pitch (up and down) and Role (rotation). On car cameras set this orientation
relative to the car frame. Chase, chopper, and blimp cameras are all relative to the platform that the
camera is mounted to. And static cameras set the orientation relative to the world coordinates. Static
aiming does not change, and therefore ignores the dampening request.

At Car – This mode aims the camera directly at the focus car, so the car is always in the center of the
display. This mode ignores the orientation vector. Dampening can be used to add a bit of variability to
the shot

At Group – This piece of code uses a complicated formula of weights to try and focus not just on the
focus car but makes sure that neighboring cars, and track surface are represented by the shot as well. In
general this should allow for a more interesting shot over aiming at the car. Again dampening can be
used to smooth out the shot and add in some randomness. Note that this shot in particular is very
sensitive to cars disappearing from the world, and will jerk around in an unsettling way if cars disappear
and reappear and dampening is not enabled to smooth out the motion.

Setting the lens with Static FOV or Zoom

The lens can either be set to a fixed field of view (width) or can dynamically set its view to try and make
the focus car take up a fixed amount of space on the display. When you select Static FOV the camera
fixes the lens to a given angle using the FOV slider. With Zoom mode the slider represents the
percentage of the car that will be visible on the display. At 100% the car will fill the display and at 25%
the car will be one forth the width of the monitor. The automatic zoom is limited in range, if the car is
too far away or to close the zoom will hit a lock and stop zooming until the car comes closer into view.
This is usually an undesirable effect, it is a good idea to zoom the camera in more in order to stop it from
occurring.

Shot selection

There are a large number of cameras set up by default in the simulator, in order to better organize the
cameras they have been combined into groups, like the TV1 camera set. Each camera in a group has the
potential to be used at any time. Some cameras have a limited shot range, they can only see the focus
car at certain points on the track. In order to filter these cameras out so they only become active when
they have a nice shot, we have the concept of Limit Shot to Range. This sets up a start and end position
along the track, starting at the starting line, that when the focus car is between, the camera has a
possibility of becoming the active camera. For every frame we check if the current camera has a good
shot, if it does not we look at all the other available cameras and randomly pick one with a good shot to
display. At any one time there may be several cameras that have a shot, you can hit ‘b’ or ‘shift-b’ to
manually select the next camera that has a good shot.

To limit a camera to only be active for a given section of track perform the following steps. Load a
replay with a car that travels at least one full lap around the track. This car will be our marker, used to
set the start/end points of our shot. Set the replay to a point where the camera you are interested in
becomes active, or select your camera directly from the group tab, by double clicking on it. Select limit
shot to range, and hit the setstart button. The setstart button will flash and the camera will be locked in
place. Now fast forward or rewind the tape until the focus car is at the start of the shot and hit the
stestart button again. You have now set the start of the shot. Repeat for the end of the shot using the
setend button

Here is a screen shot of the group tab, it will help to make the camera selection system easier to
understand. If you notice, the box on the left represents all the cameras in the active group. The box on
the right represents all the cameras not in the active group. The white cameras have a valid shot, and
the grey cameras do not. The red camera is the current active camera. The numbers under the ‘Q’
represent the shot quality for each camera, this number is feed into the random shot selection code in
order to choose the next active shot for a given time.

Miscellaneous settings

In addition to the above features there are several other settings in the camera tool that are of interest.

Is In Cockpit – this setting turns up the detail inside the cockpit while removing unnecessary pieces
of the car model. It is only available with oncar cameras.

Is beyond fence – Sets the sort order between the transparent objects on the car and the
transparent sections of the fence, if you find that the fence is being drawn behind the windshield of a
car, than toggle this flag.

Is parabolic mic – sets the microphone on the camera to be directional, so that the focus car is
louder than the neighboring cars

VanishX/VanishY – This offsets the view a bit either up and down or left and right. It is convenient
to use if you want the car to appear a little lower on the display.

Nearplane bias – This sets up the near clipping plane for the 3D rendering engine. If you find that
an object close to the camera, like a piece of fence, is disappearing than adjust this parameter to bring it
back into view. Be careful with it, setting it to small will result in strange artifacts in objects that are far
away due to an effect known as z-fighting. It is often better to move the camera rather than adjust the
nearplane bias.

Mic gain – this sets the volume of the microphone in decibels. There is a small button next to the mic
gain slider that will normalize the camera volume based on the current distance to the focus car. If you
hold down this button while a car passes, it will set the peak volume for the camera to a reasonable
level.

Camera view – camera view can be set to one of live, wide, front, side, top. It is a special mode used
to visualize the location of the camera in the world. When set to any view besides live, all the static
cameras will be drawn into the world using a simple camera model on a colored stick. Front/side/top
just forces the camera to look back at itself in order to accurately place the camera at a fixed track
location.

Use key acceleration – When editing the cameras with the keyboard an acceleration curve is
applied to the control so the longer you hold down a button, the faster the camera will move in the
world. This is desirable when placing a camera, but not when trying to edit a camera ‘live’. You can
disable the key acceleration in order to have a smoother pan/zoom experience.

Use key 10x – You can toggle on a 10x acceleration with a hot key of ‘alt-p’. This is useful for rapidly
moving a camera across the world without giving up the fine grain control in the process.

Key step factor – This adjusts the default speed at which the camera controls move at when using
the keyboard. Increasing this number moves everything faster, decreasing this number moves
everything slower. The defaults are set up in such a way that it should not be necessary to change this,
but it can be useful for fine tuning cameras, or doing live editing.
Enable automatic shot selection – Turning this off will stop the camera system from switching
cameras automatically when a car goes out of view. It gives the operator control over the shot
selection.

Use temporary edits – When this is selected, all edits to a camera will be forgotten when the
camera looses focus. This is useful in a live event when you want to manipulate a camera temporarily
but do not want the changes to be made permanent

Is scenic group – When the car we are focusing on disappears from the world, the camera system
will switch over to a scenic camera group to give the cameras a little life. Setting this to true marks the
current group as the scenic camera group.

Key Mappings

On the config tab you will find all of the keyboard mappings for the camera controls. Almost every
control can be edited with a keyboard short cut. The position (lat, lon, alt), Aiming (yaw, pitch, roll) and
zoom controls can also be mapped to an analog joystick for finer grain control during live editing. If you
want to remap a control simply click on the red button next to the control and type a key or press a
button on your joystick. If you want to cancel a key remap hit escape. And in order to get back the
default mappings, simply hit the reset button, this will not affect the calibration of your driving controls.
In order to properly support analog devices, there is a calibrate button that will let you calibrate your
joysticks. You must calibrate at least once before you can properly assign a joystick to a control.

Mouse Aim Mode

There is a special navigation mode that allows you to use the mouse to aim and fly a camera around the
track. You can enable it (once the camera tool is up) by hitting ‘ctrl-z’. Once activated, moving the
mouse will aim the camera, and hitting the mouse buttons will move you forward and back. You can hit
‘esc’ at any time to reset the camera back to its default location. Or, if you hit ‘ctrl-z’ again, the camera

tool will attempt to update the cameras location and orientation if possible for the camera type
selected. You can continue to use the keyboard to control the camera while in mouse aim mode. This
can result in very complex motions without much effort from the operator.

Director Mode

In the lower left hand corner of the session screen, there is a helmet and name of the current driver that
the camera system is following. Clicking on this helmet brings up a list of all the drivers and lets you
select what driver to follow. In addition, at the top of the list are three choices that will enable an
automatic director mode. This mode lets the camera system decide who to focus on. The choices are
‘focus on crashes’, ‘focus on leader’, and ‘most exiting’. Most exiting tries to find the cars in the tightest
race and focus on them, focus on crashes is similar to most exiting, but if a wreck occurs it will try to
jump to that instead. Focus on leader will follow the lead car, or other cars near the leader that are
interesting to watch.

Track saving and loading

At any time you can hit savetrak or savecar to write your edited cameras out to disk. The cameras are
located in ‘[My Documents]\iRacing\cameras\tracks\[track name]’ or ‘[My
Documents]\iRacing\cameras\cars\[car name]’ respectively. These files are your local copy of the
camera files, and do not affect the internal camera files already stored with the tracks and cars. You can
save multiple camera sets, and load them back up using the load track and load car buttons. From here
you can also load the default camera sets.
There are some restrictions on the camera system:

Cockpit – Cockpit is a non editable camera, you cannot make changes, and it is not saved to disk.

Car Cameras – Nose, Gearbox, Roll Bar, F Susp, and R Susp are all on car cameras and will be saved
to the car camera file for each car loaded in the sim. Everything else is a track camera and saved to the
track camera file. There can only be one car camera in each oncar group.

Miscellaneous Key Bindings

In addition to the keys used by the camera tool, the following hot keys may be helpful when editing
camera sets. Keys beginning with a kp_ are key pad keys (the number pad on the right side of your
keyboard).

ctrl-f12 – Toggle camera tool on/off.
esc – exit camera tool.
kp_7 – Jump to start of replay.
ctrl-kp_4 – Jump to start of session.
shift-kp_4 – Rewind replay.
kp_4 – Move one frame back in replay.
kp_5 – Pause playback of replay.
kp_del – Stop playback of replay.
kp_8 – Replay toggle slow motion.
kp_6 – Move one frame forward in replay.
shift-kp_6 – Fast forward replay.
ctrl-kp_6 – Jump to start of next session.
shift-kp_3 – Jump to next lap crossing for focus car.
shift-kp_1 – Jump to previous lap crossing for focus car.
ctrl-kp_3 – Jump to next incident in replay tape (may change focus car).
ctrl-kp_1 – Jump to previous incident in replay tape.
kp_1 – Jump to end of replay.
b – Select next camera in current camera group.
shift-b – Select previous camera in current camera group.
c – Select next camera group.
shift-c – Select previous camera group.
v – Focus on next car.
shift-v – Focus on previous car.
ctrl-v – Focus on the players car (your car).
ctrl-c – copy text from the active edit box.
ctrl-x – cut text from the active edit box.
ctrl-v – paste text in to the active edit box.
space – Toggle the session UI on/off.
ctrl-pgup – scale ui bigger.
ctrl- pgdn – scale ui smaller.
ctrl-alt-shift-home – toggle split ui mode on.
ctrl-alt-shift-pgup – shift split in split ui mode.
ctrl-alt-shift- pgdn – shift split in split ui mode.
p – Toggle speed and gear display.
f – Toggle system Meter display.
l – Report Latency

In addition you can key in a sequence of keys to select both the focus car and the camera group. This is particularly useful when doing video work. To select the car based on car number use the following sequence: ** . To select the focus car based on car position use: /*. In both cases you can omit either the camera number or car number by simply hitting * or enter instead. This would leave the focus car or camera unchanged while changing the other. Both the * and / keys are located on the top of the number pad.

There are a series of sliders in the options dialog that control how the driving camera operates. Below is a summary of those sliders.

• Field of view controls how zoomed in the view is. Ideally this would be set via the FOV calculator on the graphics screen, but you need your monitor to be close to your face for the calculated FOV to be worth using. If you get this 1:1 with reality the view will change just like it does in a real car, if you set it much wider than reality then everything will feel faster, not in a good way. You can adjust this in car via the [ and ] keys
• Driver height moves the driving camera up or down the same amount in all cars. Adjust this if you feel short or tall in all cars. You can adjust it on a per car basis in the camera tool by editing the z-offset. You are limited to just a few inches of adjustment here, we don’t want you moving your head outside of the car body. You can adjust this in car via the ctrl-[ and ctrl-] keys
• Shift horizon is a funky one. It moves the horizon up and down relative to the center of your monitor but does not change the camera geometry in any way. You can use this to shift the dash up into view, or ideally you would use it to move the horizon up to eye level to reduce distortion. You can adjust this in car via the shift-[ and shift-] keys.
• Roll chassis blends between your head rolling side to side with the car body or staying level with the ground. At 100% your head moves in sync with the body of the car, and at 0% your head is locked to the horizon and never rolls. Try bringing this down just a bit, say 80% to give the body of your car a bit of motion in a bank.
• Pitch chassis blends between your head pitching up and down with the car body or staying level with the ground. At 100% your head moves in sync with the body of the car, and at 0% your head is locked to the horizon and never pitches. Try bringing this down just a bit, say 80% to give the body of your car a bit of motion on a hill.
• Neck motion controls a spring in your neck that smooths out the bumps, just like your real head will roll back and forth as you go over a bump in your car. At 100% the neck spring is fully enabled, and at 0% your head is just locked to the chassis (or horizon depending on the above parameters). Try dialing this down a bit if you get sea sick in VR, or if you have a motion platform.
• Rotate with velocity will point your head in the direction of the slide. By default this is off and your head rotates in sync with the chassis of the car. Try adding in a bit, say 20% and you will see the body of the car move around a bit when you go into an under steer or over steer situation.