question

M L avatar image
M L asked ·

MaxToA How to do negative Displacement?

Hi! I'm trying to make a negative displacement. It's a seamless line arrangement that I want it to be carved 1inch in the model. with Vray i'm able to give a value of -1 to the white lines and it carves it on the box. I followed the Arnold tutorial on Displacement, even thought it says we can, i'm not able to give negative value. Either in physical material or in Arnold properties modifier..

displacement
10 |600 characters needed characters left characters exceeded

Up to 5 attachments (including images) can be used with a maximum of 2.0 MiB each and 9.8 MiB total.

Mads Drøschler avatar image
Mads Drøschler answered ·

This is easy to do.

All we need to do first is to understand ranges, especially ranges in positive space and ranges in negative space.

If we pipe a map to a displacement, it will always be going from 0-1 in the range typically, but we want this range to be set to a new range, because we CARVE, this means we got a floor and a roof.

The old roof was 1 and the floor was 0.

We use a range node to convert the space into a useful range when carving and the range we want to output is from -1 to 0, meanin displacement will only go on the negative while leaving the roof untouched.

So source into a converter, and then add a Color Correct node to flip the image around, so that stuff that needs to carve is BLACK, and stuff you dont want to move is WHITE.

See a functional carve here.

Attached a max 2016 file with working carving, and a bitmap, just reload the bitmap back in and it will work.carve-displacement.zip


werwer.gif (124.3 KiB)
cc.jpg (130.6 KiB)
1 comment Share
10 |600 characters needed characters left characters exceeded

Up to 5 attachments (including images) can be used with a maximum of 2.0 MiB each and 9.8 MiB total.

Thank you, it works! I am very impress with your solution! I will add for the people who use linked dwg geometry, that you have to add a Quadify Mesh modifier to be able to change the heights. :)

0 Likes 0 · ·
Petros Proestos avatar image
Petros Proestos answered ·

Holy s.... Mads I archive any answer you give man...

you rock...

Share
10 |600 characters needed characters left characters exceeded

Up to 5 attachments (including images) can be used with a maximum of 2.0 MiB each and 9.8 MiB total.

Lee Griggs avatar image
Lee Griggs answered ·

You could try using a Complement shader to invert the bitmap.

>I followed the Arnold tutorial on Displacement, even thought it says we can, i'm not able to give negative value.

Where does it say that?


complement.jpg (115.5 KiB)
Share
10 |600 characters needed characters left characters exceeded

Up to 5 attachments (including images) can be used with a maximum of 2.0 MiB each and 9.8 MiB total.

M L avatar image
M L answered ·

Thanks for the answer @Lee Griggs unfortunately I already tried to invert the bitmap but it displaces the groove outside instead of carve it inside..

here's what I mean:

Here's What I need: linked autocad file + vraydisp mod set at -1'' (need some tweaking..):

Ps.: and for the negative value I tought I saw, I misread: ''...This is because integer formats do not support negative pixel values, which are used by floating-point displacement maps.''


expl-large.jpg (278.0 KiB)
h.jpg (97.2 KiB)
Share
10 |600 characters needed characters left characters exceeded

Up to 5 attachments (including images) can be used with a maximum of 2.0 MiB each and 9.8 MiB total.

Write an Answer

Hint: Notify or tag a user in this post by typing @username.

Up to 5 attachments (including images) can be used with a maximum of 2.0 MiB each and 9.8 MiB total.

Welcome to the Arnold Answers community.

This is the place for Arnold renderer users everywhere to ask and answer rendering questions, and share knowledge about using Arnold, Arnold plugins, workflows and developing tools with Arnold.

If you are a new user to Arnold Answers, please first check out our FAQ and User Guide for more information.

When posting questions, please be sure to select the appropriate Space for your Arnold plugin and include the plugin version you are using.

Please include images, scene and log files whenever possible as this helps the community answer your questions.

Instructions for generating full verbosity log files are available for MtoA, MaxtoA, C4DtoA, HtoA, KtoA, and Kick.

If you are looking for Arnold Documentation and Support please visit the Arnold Support site.

To try Arnold please visit the Arnold Trial page.

Bottom No panel present for this section.