Lane Following and Line Detection

[raadkhan]

• Referenced vision node in IGVC-2017 for CMakeLists
• How does the header file look?

[raadkhan]

@garethellis0 @ValRat

LaneFollow ROS node structure:

• subscribes to camera node and receives raw image (or LineDetect::getVideo( ) should directly get the raw image from the cameras)
• instantiates LineDetect class and receives filtered image
• publishes filtered image
• angleDetermine( ) takes filtered image and gets angle of lane lines POI from image (with respect to the robot)
• magicFunction( ) takes angle and outputs a Twist message / recommended linear and angular velocity
• should also publish this Twist message?

[garethellis0]

@raadkhan

• general structure looks good
• we should have a conversation tomorrow about how to divide up filtering, line detection, twist message generation nodes. Should they all be individual ROS nodes, all in one node, or somewhere in between?
• you should assume that you are receiving images one at a time

[garethellis0]

@raadkhan - sorry, meant to get to this earlier in the day, but stuff cropped up

Review of Decisions and Whatnot from Today (Saturday, May 13th)

• The declarations for all the LaneFollow variables and functions should go in a header file
• A good example of a node that uses a sub-class to do a lot of the work for it is the GpsDecision node (it uses the GpsMover class to compute twist messages)
• We've decided to keep everything in one node, but we should publish the filtered image to it's own topic for debugging
• Try and avoid passing large objects like images by value, instead, pass them by reference. A good quick explanation can be found here
• Bonus: Smart pointers are magic, this stackoverflow answer does a good job of explaining why. You don't really need to know about this, but if you want to pass pointers and references just aren't gonna do it for ya, this is the way to go. They're also just good, useful, things to learn, and that's half the point of this team :tada:

I might have missed some stuff, feel free to reply or PM me or Val if you want clarification or help at all