## Vector displacement from arbitrary geometry : Houdini to Terragen

Started by paq, December 21, 2017, 02:55:09 pm

#### paq

##### December 21, 2017, 02:55:09 pm
Hello,

This is a first proof of concept about generating a vector displacement from any arbitrary model.
There is still a lot of unknown, and areas I need to test :

- Trying different smooth algorithm to remove overlapping geometry when flattening the model in Houdini.
(Maybe using the one used to flatten uv texture). This is the area that takes a bit a computing time.

- I wish to find a way to write negative value in .exr generated in Houdini, to avoid to do a refit from a normalized texture in Terragen (seems to work, but Min and Max value to re-apply the vector displacement map have to be entered by hand)
- Terragen smooth interpolation in the image map shader seems to wash a lot of details (especially around the ears in this case). Disable it make the model too ugly (faceted). Furthers test need to be done, maybe an higher resolution from Houdini model can helps a lot.

The result is not that bad so far
[attachimg=1]
Gameloft

#### luvsmuzik

##### December 21, 2017, 03:35:35 pm #1
That is amazing!

#### N-drju

##### December 21, 2017, 03:40:48 pm #2
Hehe, looks cool. I guess complicated terrain generation can be made easier with your solution? Unless the same amount of work is needed in Houdini for the same effect.
"This year - a factory of semiconductors. Next year - a factory of whole conductors!"

#### Hetzen

##### December 21, 2017, 04:47:35 pm #3
That's really interesting. Turning geo into vector displacements. How does Houdini do that?

#### paq

##### December 21, 2017, 05:41:46 pm #4
Hello,

Well the idea is to create a uniform skin around the object and a plane. I use voxels for that (vdb). (image 2)
That's the model A.

Then I flatten the model (scale y = 0) (image3) , and I relax the point until there is no overlapping : model B. (image 4)

Finally I subtract point position from model A with point position from model B, and that creates the vector displacement (display as vertex color in image 5)

Gameloft

#### KyL

##### December 21, 2017, 07:32:01 pm #5

Glad to see it's doable, even more in such an elegant way. Looking forward to the development on this!
Very exciting

#### bobbystahr

##### December 22, 2017, 03:04:33 pm #6
Right on paq...freakin brilliant...
something borrowed,
something Blue.
Ring out the Old.
Bring in the New
Bobby Stahr, Paracosmologist

Great work!

Nice.

#### paq

##### December 24, 2017, 01:42:55 am #9 Last Edit: December 24, 2017, 01:45:58 am by paq
[Hello and thanks !

I have a better system now, using an uv unwarp (uv-pelt) to flatten the model. (mid resolution)
Works much better, and I'm starting to  keep much more detail than the previous prototype.

For a 2K output, it takes a little while to process, about 5-10 minutes, ... mainly because I use a very slow operator in Houdini.
It's far to be a digital asset that anyone could use with predictable result,but I will share a scene and maybe a little video to explain the process.

But first I have to test more advanced structure

[attachimg=2]

[attachimg=1]
Gameloft

#### bobbystahr

##### December 24, 2017, 03:28:20 am #10
simply wow
something borrowed,
something Blue.
Ring out the Old.
Bring in the New
Bobby Stahr, Paracosmologist

#### Artice-3d

##### January 02, 2018, 11:31:46 pm #11
Hello Paq !! I like your vector displacement workflow.. One question - Tell me please - What node did you use to vector colorization ??!!

#### paq

##### January 02, 2018, 11:52:51 pm #12
Hello Artice-3d,

Just add a point wrangler, with @Cd=@P;
Gameloft

#### Artice-3d

##### January 03, 2018, 12:13:45 am #13 Last Edit: January 03, 2018, 02:02:35 am by Artice-3d
Mine not looking good as yours Geometry lost all details at all !!! Your geometry clean and beautiful!!  Please, maybe you'll make a little tutorial with your dinosaur results, it looks very good!! I even don't know how to export from houdini in proper way  ((

Ok update--- i've got clean geometry !! Need to pelt it correctly ))

#### Dune

##### January 03, 2018, 02:33:14 am #14
Brilliant work. I did some experiments in mudbox quite a while ago, but there you have to use 2 planes with equal amount of vertices, work your magic on one and subtract to vector displacement map.