A graphics rendering system (400) and method (500) are disclosed for forming object groups from input objects (431 through 438). The graphics rendering system (400) comprises an number of detection schemes (421 to 423), a managing module (410) and a rendering module (405). Each detection scheme (421 to 423) has a priority and an associated object group type, and is operative to detect whether an object forms part of an object group of the associated object group type. The managing module (410) passes data describing a received input object to at least one of the detection schemes (421 to 423), and receives notification from the detection scheme(s) whether the object forms part of the object group(s). The managing module (410) then determines whether one or more of the object groups are completely formed, where at least partly formed object groups form a list. A completely formed object group is passed by the managing module (410) to the rendering module (405) for rendering based on the priorities of the detection schemes associated with the object group types of the object groups in the set. The above avoids the need for complex inter-detection scheme communication through the management of graphic objects, detection schemes and their priorities.