ligthning challenge – 2

today i chose my model of constanza bonarelli, to learn about lightning… and, i have found something, that opened my eyes šŸ™‚

i try to explain with renders from zbrush. its about how zbrush deals with shadows, and that seems to be quite different now in z4r2 than it was in z4… so, many pics ahead, please bear with me, as i also write this down as a mental note for me. i plan to put all tidbits i learn into the new category ‘how-to-do’… so, here goes…

the first is a plain render in zbrush, just started zbrush, put skinshade4 as material with a wax setting about 25, choose a light yellow/orange as color, use the default light setting here, and hit bpr render, note the bpr shadow is set (by default) to 100 :

in the next render, i just changed the bpr shadows to 50, note that this only (!) changes the darkness of the cast shadow on the floor plane, but does NOT affect the darkness of the shadows on the model :

Now, i have dropped the light intensity from the default light from 0.85 down to 0.1386, turned off the shadows of that light, and added a directional light in the lightcap menu, with shadow strength = 100. and the result is this, note the strong shadows on the model :

then i played with the slider “shadow” in the lightcap light. despite it is a slider with range 0,1,…,100 it has only two states. 0 puts the shadows off completely, all other numbers put the shadow on, on the exacte same strength… that was confusing !!! BUT, then i found, z4r2 has (at least) one other slider that affects how shadows are rendered. and that is hidden in the material palette, under environment : it has default value 50 for shadows, the result is as seen above. setting that at 31, and leave everything else as in last render gives this (note the cast shadow on the floor plane is still as black as it was in the previous image)

and cranking this slider up to 90 gives this

…. so, the learned lesson is this : zbrush now deals (at least with) 3 sliders that affect how shadows are rendered. the bpr shadow slider affects the darkness of the floor shadow, the lightcap shadow slider can put all shadows on, or all shadows off, and nothing else, despite the 101 settings. the strength of the floor shadow is given by the bpr shadow setting, the strength of the shadow on the model is given by the shadow slider in material/environment… pretty easy, is it not ? šŸ™‚ … ok, that was rather boring tonight, but i believe it was very valuable as i now understand how to produce (at least) the shadows i want see in a render… … oh, btw, the softness slider of the shadow in the bpr menu makes all (!) shadows softer/harder, floor shadows AND shadows on the model, contrasting the action of the shadow slider in the bpr menus … its easy as i said, just not consistent in the menus…


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