Author Topic: vector displacement  (Read 1789 times)

Offline pfrancke

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vector displacement
« on: July 31, 2013, 03:36:09 AM »
very big thank you to jmeyer and the guys that are explaining the vector displacement process.  I made headway with it using zbrush to create the shape and projected it onto a flat plane.  Interesting thing I tried (that I don't think worked all that well) was to use a .1 strength negative light sun opposite a normal sun.  It added a lot of contrast, made the shadows deeper, but the red sky is coming from that direction and the exr file output acted weird in PS.  I should have saved the render as a TIF file I think...

Offline TheBadger

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Re: vector displacement
« Reply #1 on: July 31, 2013, 07:31:01 PM »
Cool!

The ground looks like fabric a little. Like the surface could just be pulled away from the world. Gives me some ideas:)
It has been eaten.

Offline mhaze

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Re: vector displacement
« Reply #2 on: August 01, 2013, 08:59:17 AM »
Interesting image.Could you give us more details about the projection process in zbrush

Offline pfrancke

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Re: vector displacement
« Reply #3 on: August 01, 2013, 12:54:19 PM »
About the image, it is an exr file displayed twice (on top of itself) where I sized down the top one.

Instructions for ZBRUSH projection (provided to me with kindness from Jochen (jmeyer) -- Thanks Jochen.

This will project "mesh1" onto a plane which in turn will be used for the vector displacement.

Let's say you have mesh1 already drawn to the canvas and are ready to go.
Now you want to import your plane.To do that go to the Tool palette and click on the
little icon with the star saying PolyMesh3D then press import and import your plane.
With the plane active go to Tool -> Morph Target -> press StoreMT.

Then Tool -> Subtool -> press Append and in the window that opens choose your
mesh1.  You should have 2 subtools now,the plane and mesh1 with the plane
as the active subtool.

Most likely mesh1 is too big to be projected right away.So click on it in the
subtool list to make it active.Now scale it to the appropriate size.Either with the transpose
line or with Tool -> Deformation -> Size.  Jochen prefers the size slider under Deformation.
So got to Tool -> Deformation -> Size and make all 3 axes active by clicking on the
grayed out ones,then pull the slider to the left or type in a value.  Then position mesh1
with the Offset slider and if needed the Rotate slider.Be sure to leave enough
space between the head and the edges of the plane.Bring mesh1 down to it's
lowest subdiv level.

Now switch subtools so that the plane is active again.  Then Tool -> Subtool -> and press
Duplicate that gives you a duplicate of the plane and with that active press the move down
arrow(the angled one) and move it to the end of the list.  This copy of the plane is just to help
with projecting a better plane to mesh1 transition.
So you should have 3 subtools now.On top of the list the plane,second mesh1
and at the end the plane duplicate.

Make the original plane (the one on top of the list) the active subtool.
To make the projection easier and for better results you want to sculpt a bit now to bring the
shape of the plane closer to the rough shape of mesh1.
Press the Transp button on the right side of the canvas and mesh1 should become
semi transparent.
Make sure that symmetry mode is active for your plane. Transform -> Activate Symmetry
If mesh1 is asymmetrical rather,than you can omit that of course.

Now bring up the part of the plane that's covered by mesh1 or a bit more,no accuracy
needed here,just get it somewhat close to the shape of mesh1.  Occasional smoothing
is recommended.
When you have a blob that's close enough it's projection time.

With the plane still the active subtool go to Tool -> Subtool -> Project ,click it open and
then set the Dist slider value to 0.3 and press Project All.
Then,plane still active, go to Tool -> Geometry -> and subdivide once,
then press Project All again,
subdivide once more and Project All again.
Set the Dist slider back to 0.02.
Now switch subtools to make mesh1 active and go to Tool -> Geometry -> and go up
one subdiv level.
Switch back to the plane subtool,subdivide again and press Project All again.

Repeat that until you have projected the highest subdiv level of mesh1.
If your model is not too complicated shapewise you can of course go up 2 or 3 levels
at once,instead of projecting each level individually.
Now you should have projected mesh1 successfully onto a plane.
You can delete mesh1 and the duplicate from the subtools list if you want.
Save your ZTool and you're done.

All you have to do now to get an exr is desribed in the VDisp tut.


Offline Dune

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Re: vector displacement
« Reply #4 on: August 01, 2013, 01:08:26 PM »
Wow. It's easier in mudbox... there you just add a second mesh (plane) after working on the first plane and you're done.

Offline mhaze

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Re: vector displacement
« Reply #5 on: August 01, 2013, 01:14:04 PM »
Cheers thanks a lot for that. Phew gonna take some sorting, wish I had mudbox!

Offline pfrancke

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Re: vector displacement
« Reply #6 on: August 01, 2013, 01:14:34 PM »
I can't speak to mudbox, (but what you said certainly sounds simple) but I was not familiar enough with zbrush to pull it off, so Jochen's instructions are extremely detailed (which was exactly what I needed).  Once you do it a couple of times, it flows very naturally.  I DID break down last night and ordered a couple of zbrush training DVDs which will probably do wonders for my ability to understand what it can do and how to go about it.  At the moment my biggest complaint/issue with ZB is that it isn't yet 64 bit (which is kind of unbelievable in today's day and age...)

Offline j meyer

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Re: vector displacement
« Reply #7 on: August 01, 2013, 03:30:13 PM »
Ulco - actually it's very easy and fast once you're familiar with the concept.
         And this technique is not meant for 2 planes,but if you want to attach
         a separate model,a head for example,to a plane to get a VD map from.
        It' s good for other -non related- things aswell.



Keep going Piet!

Offline Dune

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Re: vector displacement
« Reply #8 on: August 01, 2013, 05:32:53 PM »
Ah, thanks Jochen. That makes a difference, as I couldn't get a 'non-plane' mapped onto a plane. I'll see if this technique works in Mudbox as well.

 

anything