ZBias issue


(Wim Dekeyser) #1

The ZBias factor is not the same for different display modes - without there being a way to control this value per display mode.

The top part of this picture shows a model in the Rendered display mode (with surface edges turned on) - the bottom part is a (modified) Shaded display mode.

Raytraced uses the same ZBias as the rendered mode.


(Nathan 'jesterKing' Letwory) #2

Raytraced doesn’t know about any Rhino ZBias factor. How do you infer it to use the same?


(Wim Dekeyser) #3

Just by Raytraced having the same bleeding of edges through the surfaces as I see in Rendered. I didn’t try to imply that Raytraced uses that factor actively in its display - just that it seems to be using the same “information”.


(Nathan 'jesterKing' Letwory) #4

Can you please create a simple test file that shows the problem. If you have time please add screenshots with the error and what you expect to see.

Thanks in advance.

/Nathan


(Wim Dekeyser) #5

That turned out to be a bit harder than I thought it would be… It seems to be related to a few 3rd party components that we use.

Anyway, here is a simplified scene but because of the simplification, the effect is less pronounced. It is much more visible in the screen shot that I posted above.

ZBias Test File - 3.7z (4.6 MB)

What I see:
image

What I expect to see [and was obtained by setting the ZBias factor to .1]:
image

Why I expect that? Because shaded display modes are less dirty with the default ZBias factor:
image


(Nathan 'jesterKing' Letwory) #6

@wim, is that with extra goodies turned on, on top of the Raytraced view? I.e. wires and such? Those I am not drawing myself, so may be the same problem as what Rendered view shows…


(Wim Dekeyser) #7

@nathanletwory, as in my opening post: this is “the Rendered display mode (with surface edges turned on)”.

It was only in an additional comment that I wrote that this was also visible in the Raytraced mode. That makes sense, then, since you are not drawing those wires…

At any rate, I suppose this is something for @jeff or @stevebaer to take a look at.


(Nathan 'jesterKing' Letwory) #8

@wim, I apparently need to do more “begrijpend lezen”. The surface edge drawing is indeed more @jeef, @stevebaer or @DavidEranen territory.

I have reported this as RH-41155 to track.


(Wim Dekeyser) #9

No worries, Nathan! It takes two to tango…

(by the way, could you make that YT open to the public?)


(Nathan 'jesterKing' Letwory) #10

Done.