> Quote - > I am relatively new to Poser (Pro 2010). > > I am confused about 'displacement' and what limitations there are with regard to JPG files which I apply to a 'Square Hi-Res' Prop. > The Preview and Firefly renders both appear to blur (anti-alias?) pixels, and 'displacement' appears to calculate an average. Looks excellent from afar, but indistint with the regard to the original image's quality.

A displacement map and bump map, both store the same information, they can be interpreted as height maps storing sample values of the height (displacement) of the surface of a (real) object relative to the surface of a model. But because it stores only sample values, not a continuous surface, but the renderer renders surfaces (at least in theory) and not sample values, the renderer has to interpolate these sample values to get a surface. It does so by using linear interpolation, and because of that the object always gets blurred. You can somewhat minimize the blurring by disabling texture filtering, but cannot completely get rid of it. You can however use a higher resolution texture or (in the case of bump maps) use a tangent space normal map; the latter one explicitly contains normal values, not height values, and therefore no interpolation is needed to render them, so there is usually less blur.

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And whether there is ever any reason to use 'displacement' and 'bump' in the same shader?

I guess the usual reason (at least for me) is, that you can disable the displacement in the render settings (because you want to get a fast preview), but still get a similar impression how your surface looks like with displacement enabled. But your doubt is justified as the illustration shows; i used a white rectangular spot on a black background for a texture, and rendered it as bump, displacement and both (lit at a shallow angle from the left). As you can see, the displacement and bump are indistinguishable when looked straight on, but when both displacement and bump are used with the same map, the bump map gets applied on top of the already displaced surface, which is wrong. (On the other hand, Poser rendering is not exactly rocket science, so anything that looks good, is allowed :-)