Vision#
Introduction#
The Vision category includes blocks that allow your robot to interact with visual information using a VEX IQ Vision Sensor. These blocks let the robot take snapshots of its surroundings, identify objects by color signature, and report properties like size, location, and angle.
Below is a list of available blocks:
take vision snapshot – Captures a snapshot using a selected Vision Sensor and signature.
set vision object item – Specifies which detected object (by order) to reference in object-related blocks.
vision object count – Returns the number of detected objects in the snapshot.
vision object exists? – Returns a Boolean indicating whether a detected object is present.
vision object property – Returns details such as:
take vision snapshot#
The take vision snapshot block will capture the current image from the Vision Sensor to be processed and analyzed for color signatures or color codes.
Colors signatures and color codes must be configured first in the Vision Sensor Utility before they can be used with this block.
Note: A snapshot is required first before using any other Vision Sensor blocks.
The dataset stores objects ordered from largest to smallest by width, starting at index 0. Each object’s properties can be accessed using vision object property block. An empty dataset is returned if no matching objects are detected.
take a [Vision1 v] snapshot of [SELECT_A_SIG v]
Parameter |
Description |
|---|---|
vision sensor |
The Vision Sensor to use, configured in the Devices window. |
signature |
Filters the dataset to only include data of the specified color signature or color code. |
Example
set vision object index#
The set vision object index block sets which item in the dataset to use.
set [Vision1 v] object index to [1]
Parameter |
Description |
|---|---|
vision sensor |
The Vision Sensor to use, configured in the Devices window. |
index |
The number of the item in the dataset to use. |
Example
vision object count#
The vision object count block returns the number of detected objects in the dataset as an integer.
([Vision1 v] object count)
Parameters |
Description |
|---|---|
vision sensor |
The Vision Sensor to use, configured in the Devices window. |
Example
vision object exists?#
The vision object exists? block returns a Boolean indicating whether a specified color signature or color code is detected in the dataset.
True – The dataset includes the color signature or color code.
False – The dataset does not include the color signature or color code.
<[Vision1 v] object exists?>
Parameters |
Description |
|---|---|
vision sensor |
The Vision Sensor to use, configured in the Devices window. |
Example
vision object property#
There are nine properties that are included with each object (shown below) stored after the take vision snapshot block is used.
([Vision1 v] object [width v])
Some property values are based off of the detected color signature’s or color code’s position in the Vision Sensor’s view at the time that the take vision snapshot block was used. The Vision Sensor has a resolution of 316 by 212 pixels.
Parameter |
Description |
|---|---|
vision sensor |
The Vision Sensor to use, configured in the Devices window. |
property |
Which property of the detected object to use: |
width#
width returns the width of the detected color signature in pixels as an integer from 0 to 316.
[Vision1 v] object [width v]
Example
when started :: hat events
[Move towards a blue barrel until its width is larger than 100 pixels.]
forever
get [blue barrel v] data from AI Vision
if <AI Vision object exists?> then
if <(AI Vision object [width v]) [math_less_than v] [100]> then
move [forward v]
end
else
stop all movement
height#
height returns the height of the detected color signature in pixels as an integer from 0 to 212.
[Vision1 v] object [height v]
Example
when started :: hat events
[Move towards a blue barrel until its height is larger than 100 pixels.]
forever
get [blue barrel v] data from AI Vision
if <AI Vision object exists?> then
if <(AI Vision object [height v]) [math_less_than v] [100]> then
move [forward v]
end
else
stop all movement
centerX#
centerX returns the x-coordinate of the center of the detected color signature in pixels as an integer from 0 to 316.
[Vision1 v] object [centerX v]
Example
when started :: hat events
[Turn slowly until a blue barrel is centered in front of the robot.]
set turn velocity to [30] %
turn [right v]
forever
get [blue barrel v] data from AI Vision
if <AI Vision object exists?> then
if <[140] [math_less_than v] (AI Vision object [centerX v]) [math_less_than v] [180]> then
stop all movement
centerY#
centerY returns the y-coordinate of the center of the detected objcolor signature in pixels as an integer from 0 to 212.
[Vision1 v] object [centerY v]
Example
when started :: hat events
[Move towards a blue barrel until its center y-coordinate is more than 140 pixels.]
forever
get [blue barrel v] data from AI Vision
if <AI Vision object exists?> then
if <(AI Vision object [centerY v]) [math_less_than v] [140]> then
move [forward v]
end
else
stop all movement
angle#
angle returns the orientation of the detected color code as an integer in degrees from 0 to 180.
[Vision1 v] object [angle v]
Example
when started :: hat events
[Slide left or right depending on how the Color Code is rotated.]
forever
get [Red_Blue v] data from AI Vision
if <AI Vision object exists?> then
if <[50] [math_less_than v] (AI Vision object [rotation v]) [math_less_than v] [100]> then
move [right v]
else if <[270] [math_less_than v] (AI Vision object [rotation v]) [math_less_than v] [330]> then
move [left v]
else
stop all movement
end
else
stop all movement