Is there a particle system in RealityKit? if so can some one point me to the correct documentation/articles ?

As the title says, a random crash is happening for iOS 17.0.2, when the user clicks on simple text field in wkwebview, while device locked in AAC mode, was not able to trace out the pattern, I am attaching the screenshot of the crash log from Xcode Organizer Screenshot:-

We have color images as reference images and they do work great, but the problem we are facing is as following, what we have is a coloring book for children, a sample image from the book is like below 1.This is what a physical Reference Image will look like Now coming to our use case, as i mentioned this is a coloringbook for children, so I tried to create a worst case(use as many colors as possible and color as much of the white space as possible) scenario image which looks like this Worst case physical image can be Now the issue is with the point 2, the arkit is not able to the image at all, I assume because I have used enough colors that now arkit looks at it as different image compared to the given referenceImage. Is there any way I can detect the worst case of the image also, may be by using monochrome(black and white) images? please suggest

We are using realitykit, we have reference images, and we are able to detect the said reference image, now I want to dynamically capture the region from the camera stream where the physical image has appeared, not the whole screen but only the exact physical image region.?