Forward mapping is provided, which accumulates and resolves over all samples forward mapped to each pixel bin. During accumulation and resolution of each of the samples, since a point sample from a forefront object and a point sample from an occluded object may be received by the same bin, wherein only the former should be accumulated and resolved according to the accumulation and resolution process, a Z-range, or Z-interval, is assigned to each sample instead of the conventional Z-value. The Z-range is a function of the Z-value. Analysis of the overlapping of these Z-ranges then determines which samples are to be accumulated and resolved together according to the accumulation and resolution process, and which are not.