Can anyone explain this ShowzBuffer issue?
When I zoom in i get exactly what I need but when I zoom out to see the whole object the contrast disappears.
I am laser etching the surface into brass for a friend and need the high contrast image for Lightburn so it will etch the depth correctly.
Any assistance would be appreciated.
Cheers
Geoff.
Based on a quick experiment it appears the ZBuffer values depend on the overall depth of the scene. You might try isolated only the objects you need to reduce the overall depth.
Hi David,
The object is the only thing in the scene and it is ony 20mm high.
I tried scaling it down in 1 dimension but that didn’t help (and seems like a weird thing to need to do.)
Is there any way of controlling the depth to greyscale relationship?
ShowZBuffer will only give you 8 bit greyscale (256 levels)
You need to do a rendered image with Show Distance Channel, circled in image.
You can save as EXR to get a greyscale with more than 256 levels, then you could use image processing to change the contrast.
I forgot to mention ShowZBuffer and Show Distance Channel are currently broken in v8
Z buffer has only 256 levels. And objects need to be well distributed. I might cheat a bit by reducing the thickness of the thickest objects. Or using only the face and hands without the case. Then do the case separate and composite? All those tricks might work. Could just even do the face by itself.
HI All,
Thanks for the advice, and 256 is the perfect number of greys for my purposes.
I found a solution which basically entailed making a large plane and sitting it just below the lowest surface that I wanted in the depth map.
This changed the contrast. I was able to tune the contrast by changing the size of the plane.
I have no idea why it works but it does. 
Thanks for all of the suggestions, they led me on a path of discovery.
Cheers,
Geoff,
