Figure 6. PTM-reconstructed view (no enhancement) of trace fossils (Cruziana tenella), positive hyporelief, Lower Cambrian Mickwitzia Sandstone, Västergötland, Sweden. SMNH X3527. A small number of virtual a finite number of virtual light positions can be set by clicking and dragging on the image, simulating the effect from the QuickTime-movie (greater number of virtual light settings; dragging option) and the PTM file (full PTM interactivity).