Hi all,

i was playing today with the noise functions in Houdini Apprentice and MoI (plus other tools).
The idea was to generate a lightweight NURBS model from a heavy polygon mesh. Hope you like!


talking deathclaw



Regards
Stefan

that's really cool. i like it.

Appetizing pastry!

Thanks Anthony and Pilou.

Regards
Stefan

Dang nice!

How did you do it? One by one, or is there an easy way?
(You should know, I always look for the easy way, I am the Marquis de Lazy)

hehe ;-)

Hi,

first I used Houdini Apprentice to generate the displaced noise mesh on a planar surface.
Then I brought the mesh into ZBrush for a bit smoothing. After that I generated a normal
map from the mesh and used it in Knald to generate a height map. Once you have a height
map you can then simply use the free program Zsurf to generate the NURBS surface. In MoI
I extruded the edges and once I had the sides I trimmed them and added a planar surface
to obtain a solid. The lines you see in the solid are from trimming, so that one can use
the separated surfaces for colorizing.

Regards
Stefan

P.S. This workflow could be drastically shortened if Texture Generators could generate
those noise textures on the fly, but when i did a Google image search for my texture
it found nothing which could lead to such a software … :-(



Regards
Stefan

Wow!

Well maybe I miss somethingl, but why not just export the grid as .obj and use the new Sub-D importer in Moi ?
It gives very clean (smooth) result ! ... but I wouldn't go over a 256*256 points grid.

Heightfiled is a nice and relatively easy entry point to learn Houdini.

Hi PaQ,

thanks for the valuable tip, much appreciated!

I am no Houdini expert like you, but sometimes I read interesting things
which i see in .pdf's or on GitHub and then the next thing is googling up
the keywords in combination with either Houdini or Blender. So maybe
not an optimal workflow what i did, but at least it works for me.

I will check out the heightfields options too, thanks!

Regards
Stefan

To answer your question, PaQ.

The grid was very dense and a bit spikey at the peaks.
I could convert it with MoI and the result was good, but
file size, compared to Zsurf, was much bigger.

Regards
Stefan

Maybe you can have this sort of textures with the Free Genetica Viewer! ;)
Hundred of textures can be edited!
http://spiralgraphics.biz/viewer/index.htm

ps nothing to do with diffusion / reaction ?

Hi Pilou,

thanks, but i think it is not in there and to answer your
question, no it is not a Reaction Diffusion pattern.

@PaQ in case you are still following this thread, can
you archive also an importable and smooth noise
pattern into MoI, like you have shown, when using
the Unified Noise examples 8 and 14?

www.sidefx.com/docs/houdini/nodes/vop/unifiednoise.html

If so then i think we all would very much appreciate how to
archive such a result, because if you look closely at the shown
examples they both are spikey in some areas too.

Regards
Stefan

My try

Hi Pilou,

interesting!

I have also now build PaQ's node set-up and Heightfields contain
also the flow and Perlin noise functions and i only must figure out
now how to get the initial result PaQ shows, because i have now
only nice smooth mountains like shapes but not the desired ones
like i had instantly with Unified Noise …

Anyways thanks a lot PaQ, your set-up should do the trick!

Regards
Stefan

Hi Stefan,

I hope you understand I'm not trying to patronize you, I'm actually very happy to see Houdini poping in this forum :)

The spikes are indeed a side effect (!) of having to much information in the noise, and not enough points to sample it precisely.

So here's a test using a quadball (it's easy to build with the ray operator, but you can also install the gamedev tools), and the the unified noise. I had to reduce the warp from 6 to 5.
You can also filter the noise using either a smooth operator, or an attribute blur one. I still prefer the old attribute blur, as is seems (for me) to do a better job on the spikes without removing too much details.

Beside, kudo to Michael for the sub-d importer, this baby has 1.5M quads :P (but only 6 surfaces).

An other solution is the sample the noise inside a vdb (voxel) sphere. You will get less spikes, but the topology is kinda weird and I don't think the sub-d importer will appreciate it.

++

And this by Max Smirnov ? Random curves (there is also Distort Curves)

Hi Stefan,

To create the effect you are looking for, you can remap the noise with a sinusoidal ramp.
I don't think there is a way to <sin> the noise otherwise with the heightfield, but you can send elevation from HF the COP context, do the sin function on the noise, and bring the information back as an HF. (I can prepare a little setup for this if you are interested).

There are some nice functions in the HF toolset, like the "project from object", so you can bring any kind of geometry (text) to create bas-relief (?).

Cheers.

Hi PaQ,

thanks so much for the detailed explanations and samples you have provided!

I will take a close look and what your are saying about the heightfields sounds very interesting!

For sure I will also check out what the result is when bringing in a model when using heightfields.

And I tried from your example to bring in a mesh into MoI and voila smooth and clean result! :-)

Regarding the spikes, i have to check that out with blur because smooth gave me not much visible
results.

Best regards and thanks again,
Stefan

Hi PaQ,

> I don't think there is a way to <sin> the noise otherwise with the heightfield, but you can send elevation from HF the COP
> context, do the sin function on the noise, and bring the information back as an HF. (I can prepare a little setup for this if
> you are interested).

Yes, please prepare such a set-up. It is so helpful to learn from pros like you!

Regards
Stefan