Abstract: In a data processing system, a stored environmental model of a wireless communication system is selected. The model locates at least one object in relation to a transmitter. A parent image node is created in an image tree, wherein the parent image node is associated with the transmitter. Child image nodes are created in the image tree only for each object that can redirect a propagating signal from the transmitter with a signal characteristic that exceeds a threshold. The child image node is associated with an object energized by the transmitter, and a corresponding child image in the environment model. Next, a point of interest in the environmental model is selected. Thereafter, an accounting is made for contributions to the signal characteristic at the selected point of interest from each of the child images corresponding to the child image nodes.