ZBrushCentral

clipping plane question.

ZBrush Artworks
#1

Still trying to nut out exactly where everything is in the Z space and how objects relate to the clipping plane.

So far I understand that:

• the document has a Z depth of 4096 pixels on either side of the zero point.

• the clipping plane resides at twice the canvas width, so a canvas of 640 would place the clipping plane 1280 pixels behind the zero point.

One question I have is: can the clipping plane be moved relative to the zero point.

I notice that if I fill a layer the layer seems to fill at the zero point not the clipping plane. A filled layer seems to act like the clipping plane except that it is at the zero point rather than at twice the width of the canvas.

WHAT THE HELL IS THE CLIPPING PLANE USED FOR?

When a layer is displaced on the z axis does this mean that the clipping plane can be moved along the z depth so that it sits on the canvas?

Appreciate it if someone can sort this out.

#2

a clipping plane is a plane flying at Low Altitude and hits the side of the mountain and clips a wing off
(cliping plane)
or you can go here for a zbrush indepth look at clipping plane zbrush style http://zbrush.cjb.net

#3

EZ it is ironic that you post a link to uphams site as I was looking at it in conjunction with the manual that finally confused me completely. Upham talks about an object that is disappearing through the canvas layer as if it was disappearing through the clipping plane. Also he talks of the Zero point as having 500 pixels either side of it, I do not understand where this comes from as I thought there were 4096 pixels on either side of the clipping plane.

Everyone seems to have a different understanding of how it behaves.

Also I note in the manual it says that painting with Zdepth off will apply material behind the clipping plane but it doesn’t actually say where it applies it. Like does it put it on the canvas? And why does flat render make it visible? Does any one understand this, or is this just one of those things that no one understands or cares about?

#4

what is clipping plane used for…
ok ill give you my personal input and i could be wrong a clipping plane is actuley the background which would be the furthise away from the starting point a clipping plane is nothing more then the background.
i think that zbrush is pre set for each starting point to be set half way so its away from the clipping plane.
think of a box and put a object in it if it set by the clipping plane or by the back of the box when you rotate it then it will get into it hiting it.
if its set half way in the middle when you rotate it then the chance’s are slim,

#5

From something that Pixolator said at some point (I’m not even sure when or where anymore), my understanding is that the clipping plane is an internal part of how ZBrush operates. Painting with ZADD turned off still does paint color in the places that don’t have pixols, but those pixols are behind the clipping plane, and therefore invisible. I’m afraid that I really don’t understand much more than that.

Yes, a filled layer sits at the 0 point. But you can easily change that through the Layer palette modifiers. By entering a new depth, you move the layer. And can even move it to be just 1 pixol in front of the clipping plane to give yourself the maximum amount of depth to work with in your scene.

#6

Aha, thanks aurick, but…

what about that space between the clipping plane and the canvas? Is this a no mans land.

#7

Hi Thelonious,

This clipping plane thing was one of the most confusing things about ZBrush when I first started. I haven’t fully figured it out yet, but here’s what I think. The clipping plane is the furthest back part of the z void (z-oid) that is the working space, behind it is where everything disappears, never to be seen again. New objects that are drawn seem to be placed with their middle point on this plane so that they’re half in and out of this limbo. If you drag that object forward and then create a new layer,the new layer will occur at the center point of that object. This is to say that a “layer” doesn’t exist until an object is created or zadd painting is done, and then that layer can be moved forward from the clipping plane and any new layer is created at the point where the first layer is. The clipping plane is fixed at the back of the space and layers can be moved independantly. I could be totally wrong, but that’s what I get by with right now. (I’m gonna go read the manual now :rolleyes: ) Here’s an example of some fun you can have with the clipping plane. Fill the canvas with FlatColor material and a color and draw modeled objects in FlatColor material also,(but with a different color) and let them sink into the clipping plane.

I use the FlatColor material so that when I use other objects with other materials, they will only cast shadows on themselves, not the background :cool:

#8

thanks Zoid

<BLOCKQUOTE>quote:</font><HR> New objects that are drawn seem to be placed with their middle point on this plane so that they’re half in and out of this limbo. <HR></BLOCKQUOTE>

One thing I have discovered this evening is that there is a button in the preferences palette. modifiers>picker>auto front, which, when press draws the object in front of the clipping plane. This is where I started to get confused as I always have only seen references to objects automatically drawn on the clipping plane. I’ll digest the rest of your post and report back.

EDIT: I’ve just reloaded the default config to check it and to my surprise it has “auto front” enabled so I don’t understand how come as far as I remember objects used to always be drawn half in and half out of the clipping plane. Now I’m totally confused.

#9

You are a very observant fellow. I never knew that part about the default-picker-preferences thing. It’s true, if you draw an object with no material filling the canvas, a rotated object will not intersect the clipping plane. I always fill the canvas with a material first, which is why when I then draw an object, it goes into the clipping plane when rotated.

I am about to go on vacation for two weeks, so any further revelations about this will be lost on me until I return. I will probably also miss the granting of your first star and the sad bio that accompanies it, but I look forward to reading it when I return. Keep up the good work :cool:

#10

A question from the clueless Zbrush Newbie:

(Please dont laugh)

I had no I dea that ZBrush was 3d. I though it just looked like that!
You learn something every day I guess.
So, how do you rotate your picture.

David

#11

What I meant to say wat, how do you manipulatte all three dimensions in ZBrush??

david

#12

Zoid, I think what gets confusing is the terms get used interchangably.

there is the canvas then there is the clipping plane then there is the zero point which is where a material goes when you fill a layer. On the default document the clipping plane is 1280 pixels behing the zero point. So when you talk of filling the canvas with flat colour you actually mean filling the zero point with flat colour, the object is then disappearing at the zero point not the clipping plane…my head hurts…

#13

who better knows this program more then anyone http://pixologic.com
go there under the download tab chose the PDF Manual tutorail it will explain about clipping plane.

and for dave if your a newbie you can see some 3D in action like watching a movie go to ZSCRIPT on top left and chose LOAD and look for a folder says SAMPLE MODEL and chose one now look at the very button in the center you will have a PLAY button click it and watch

got the pic off the pdf Manual form pixologic

#14

Hi there zerobugetgamemaker, (don’t worry about the arthritis, your name was still in the clipboard).

You can’t rotate the whole scene, ZBrush has a fixed camera. You can only rotate the objects while they are in edit mode. After an object is dropped it is no longer 3D although materials and object always keep their depth information for the visible bits.

However you can load a texture like a picture for example and load it onto a 3D object like a plane 3D and you can rotate the plane. Because objects don’t get smaller as they recede into the distance it is sometime difficult to tell where you are in Zspace this is where the info palette can help. but as you can see from this thread there are many mysteries in the world of Zbrush.

#15

This stuff is getting so confusing for dumb little me, that I think until I get a bigger head, Im gonna stick with two dimensions. Unless I can figure out what you people are talking about…

David

9975 more posts till I get a star

#16

just a mere 900 something will do, z!

thanks for bringing this up, thelonious and thanks for these brilliant technique, Zoid! :+1: :+1: :+1: happy vacations!

  • juandel
#17

Another question.

HOW CAN YOU TELL WHERE THE LAYER IS?

for example if you open a new document and select a texture and fill the layer, the layer will be filled at the zero point. The clipping plane is lurking at a depth of 1280 pixels (in a default doc). If you go to the layer palette and displace the z by 1275 it will now be sitting 5 pixels in front of the clipping plane. However the slider returns to Zero! So it seems that you have to remember where the layer is. It does not show any movement in the transform palette.

If you now go back to the layer palette and type “1” into the displace field you will move the layer back one pixel so it is only four pixels from the clipping plane. So it seems that movements in the Zdisplace are cumulative, I find the logic here diffucult to follow.

You can keep adding “1” to the layer till it goes behind the clipping plane but at no time can you tell where it is.

#18

Your saying that filling a layer is zero point and is the cliping plane.
do this draw a sphere activate the gyro and see how may stroke’s it take to enter the cliping plane.
ok now Fill canvas with texture and repeat and watch how many strokes.
so if the cliping plane is zero point and fill layer with texture is zero point you should have the same amount of stroke or pretty close to it but you don’t.
now if you fill layer one with texture then go to layer two and fill texture you would think that it would over lap the first layer but it wont i think by adding a layer sets it away from the cliping plane in incerments when a layer is added.
go read the PDF to get the true facts :wink:
my guess is the cliping plane is Z,4096 the default setting is Z,0 and before the default setting is
Z,-4096

#19

There’s a very easy way to tell where a layer is – or more precisely, where the contents of a layer are.

If you open Transform>Modifiers>Info you will see that the sliders change value even though you are in Draw mode. They are showing you the XYZ coordinates of the pixol immediately under your cursor. I actually moved those sliders into my Float Menu, so that they are visible to me at all times (comes in handy when I’m using the gyros, too!).

#20

Aurick,

I see now, I was watching the info but I can now see that I must move the cursor to activate the info palette Z depth.

However I now have found another puzzling anomoly: If I fill a layer at the depth of zero I find that I can move it back an forth as long as it stays in front of the clipping plane but if the layer moves even one pixel behind the clipping plane I cannot retrieve it even though it still shows up in the layer palette. Why?

EZ,

<BLOCKQUOTE>quote:</font><HR> Your saying that filling a layer is zero point and is the cliping plane. <HR></BLOCKQUOTE>

No, I am not saying this at all. I’m saying…

<BLOCKQUOTE>quote:</font><HR> if you open a new document and select a texture and fill the layer, the layer will be filled at the zero point. The clipping plane is lurking at a depth of 1280 pixels (in a default doc). <HR></BLOCKQUOTE>