ZBrushCentral

Help with displacement map

ZBrush Usage Questions
#1

Hello,

I have a brick wall that i made, it consists on a plane and all the bricks as independent tools. I made it in a way that it tiles if you look it in orthographic view front side.
Now, i want to render a displacement map from that view. Is that possible?
I tried to do it but it just renders displacement of independent tools, if i merge all of them Zbrush crashes because of too many polygons. I guess it could be done if I make a planar UVs from the front view, but i do not find the way.

Thanks in advance!

#2

If you want to create a displacement map that you can use on a plane, all you need to so is:

  1. Set up the document size to be the size of map you want. To do this:
    a) Turn off Edit (T) and clear the canvas (Ctrl+N)
    b) In the Document palette, turn off Document>Pro and set the Document>Height and Width to the size you want.
    c) Press Document>Resize
  2. Draw your model on the canvas by clicking and dragging downwards, then turn on Edit (T).
  3. Position the model so that it fills the canvas. You can use the Document>Zoom so you can see all the canvas if necessary. This won’t affect the result.
  4. When you’re happy, in the Alpha palette press Alpha>Transfer>GrabDoc. This will create a new alpha that you can export by pressing the Alpha>Export button.
#3

Thanks for your answer, i tried it but i still could not get my displacement map.
Maybe i am not been clear enough, perhaps with some pictures:

I modeled this brick wall, all the bricks are independent subtools:

Untitled-1.jpg

And i want to get a displacement map from this view so i can put it on a plane on 3ds max or marmoset and get all the details:

Untitled-2.jpg
Untitled-2.jpg1201×1146 137 KB

Thanks again!

#4

You need to upload your pictures to ZBC.

#5

Done! >.<

#6

Thanks. So what went wrong with the method I gave you?

#7

With your method i get this image, but it does not get all the small details from the high poly model:

ZGrab02.jpg

#8

That doesn’t look right. What is the number of points? Did you try merging them down into a single tool?

#9

I tried merging all the subtools but zbrush crashes because of the number of polys.
Maybe i missing something when i follow marcus instructions?

#10

No, Doug thinks that the method I’ve outlined is the same as usual displacement creation. It isn’t. :wink:

The image will be 16 bits per channel using the method I outlined. This should be perfectly OK to capture the detail in your model, and would be no different from the default displacement map created by ZBrush. Also, because monitors only display 8 bits per channel colour you won’t be able to see all the detail. It’s best to actually use it as a displacement map before deciding the detail isn’t there. There’s a simple way to test it in ZBrush:

  1. Immediately after creating the map as I described press Alpha>Transfer>CropAndFill.

What this does is use the alpha you’ve just created to fill the canvas with depth. It’s important to do it immediately after creating the map because ZBrush uses the value in the Alpha Depth Factor slider to set the depth scale. (This value is worth making a note of because it may be useful in your rendering software too when using the map to create displacement.)

The one thing that will make a difference to the detail is the size of your map (therefore the size of canvas you are using to create the map). A map of 1024 pixels square has only about a million pixels so can only capture a maximum of a million polys. Anything over that and detail will be lost.

#11

Here’s a quick example made using the method I outlined.

The white brick wall is the model I threw together using the bricks IMM brush included with ZBrush. (I didn’t make any effort to make it tileable). I added a plane, with some noise applied to it, for the mortar.

The red brick wall is a plane deformed with a displacement map created using the above method. I actually used a plugin I wrote to quickly produce this, but only because I wanted to stay in ZBrush. You don’t need the plugin if you’re exporting the map but if you’re interested it is here:
http://www.zbrushcentral.com/showthread.php?172391-Useful-small-ZScripts-and-Macros-for-ZBrush-4R6&p=979836&viewfull=1#post979836

Attachments

Bricks.jpg

#12

You were right! i tried the displacement map that i posted above on my 3d software and it worked as i needed!

Untitled-18.jpg

I can’t thank you enough!

#13

Great! I’m glad all is OK.