Incorrect zdepth map for scenes without physical background

Started by nameless, August 18, 2017, 04:57:32 PM

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nameless

1). Most of lens blur filters want dark values to be background and bright values to be foreground. Keyshot does other way. I'd suggest inverting the default, or adding option to invert values.

2). zdpeth passes in render files are always blown out to white solid color, which can be easily fixed by copying zdepth layer (I tend to include passes into single psd file for compact workflow) to new document, enabling Adjustments -> HDR Toning -> Equalize harmonogram and copying back to render file for post process. Why not let Keyshot adjust ranges and adjust zdepth properly, or give few options to let user tweak exposure of zdepth, thus simplifying workflow?

3). Biggest issue and most important to me is that makes it more difficult/less efficient to do post process blur from zdepth. If 3D scene has no physical background such as ramp or infinite floor, zdepth replaces it with black solid color. It can't be set to be alpha, nor it's possible to change color (it doesn't have to be black/white, it can be somewhere in middle, depending on project). It would be best if background was matched to depth value ends (black if dark values represent background and vice versa).

I'm not coder, but isn't inverting value range and changing fake background in zdepth pass not technically difficult matter to tackle on? It would help immensely with post production blur. Adding physical background to scene is a workaround, but it has cons in prolonging rendering times by many miles and giving you less control over model lighting due to background bouncing light.

PS Are there any plans for extending in-render lens blur options? Focus range, thresholds, bokeh shapes and textures, and so on?

Cheers,

DriesV

Some background...
The Depth pass in KeyShot is correct, in so far that it contains precise camera distance data. Many other rendering tools follow the same convention.
The Depth pass provides non-antialised, non-normalized depth data in the form of distances to the camera. Non-normalized means that the depth values are actual distances in front of camera and do not lay between 0 and 1. Hence why the Depth pass appears white when opened in Photoshop.
You must divide the depth values by the distance of the furthest surface to get 0-1 values.

It could make sense to add options for normalizing and inverting the Depth pass. However, that will complicate the UI. We will take it into consideration.

Dries

nameless

That's literally few checkboxes, it can't complicate UI that much if I have to be frank. And it would make workflow much more versatile and faster since it omits the necessity to do physical blur (so basically make few quick renders from different angles and apply blur in post process, which is fast and easy to control. Only drawback would be inability to blur correctly opaque materials).

Alright, cool it's being considered, please take matching zdepth background color to value range ends as well :)