Looking to dive into houdini

[RayLeblancArt]

Hello. I have been messing with houdini, and so far been having a blast. I love the idea of procedural modelling complex objects, the particles are insane, etc etc. I have been eating through tutorials and having a lot of fun. It looks like I will have to dedicate a lot of time to really get to know houdini though, as it is really complex. 

Does anyone know of some free tutorials, that will explain how to import complex obj that already has UV and is textured into houdini? What I have in mind ultimately, is to animate or just pose human figures in daz studio, then bring them into houdini, add hair, simulate clothes dynamics and render. Of course add some cool effects when needed.  Also, I like to do texture and detail sculpting in zbrush, I am bummed out there is no GoZ with houdini. If I can figure out a good pipeline between these two programs, I will be all set, it's all that is holding me back. 

[Annon]

Alembic would be the first thing I'd look at:

http://www.daz3d.com/alembic-exporter-for-daz-studio

[RayLeblancArt]

I think it all just works so much differently than I am used to. I tried both alembic and obj, but I couldn't find "poly groups"(no idea what that would be called in houdini) anywhere. After fiddling around, it seems they do exist in both those formats, I found that out through using the selection option of select groups or connected geometry. I see all the groups exist, and on a cursory glance, they all seem to be correct, I just have no idea how to use them or even see them in houdini. 

 

I am pretty familiar with blender and maya, houdini is a very different animal though. I was afraid I would have to create all the groups again from scratch, now I see that is not the case. I am going to watch the custom shaders tutorial from sidefx now, hopefully after then I will know how to make some basic shaders and apply it to a test model. I started watching the one on UV and materials, and that scared me. I saw that no uv nodes loaded in with the obj, I thought all of the groups were just gone. I do not like manual UV mapping, at least not on my human models that already have that done lol. 

[michael]

when you import an OBJ you can go into the Geometry Context and MMB on any of the nodes (like the file node) and you will see a listing of the attributes - P, N and uv (if it exists)...

also you can switch the viewport to UV (spacebar + 5) to see the uv's

[Fenolis]

While it's true that Houdini and Maya/Blender are quite different in the way they handle, I've used Houdini for a while now (switched from Maya almost a year ago) and I very much prefer the flexibility it offers.

 

As for your confusion, Houdini does have groups and will bring in UVs from imported geometry (if they exist). You can create a Group node in the network view to see the different ways you can group objects (bounding box is usually the most convenient for me). You can check for existing groups in imported geometry by middle-mouse clicking the File node - this will also show if the geometry has UV attributes. If desired, you can append a Material node to test your shader. Use the Group parameter to call in the group you wish to apply the shader to. If you haven't yet created a shader but wish to view the UVs, you can use a UVQuickShade node for clarity.

 

Hope this helps!

 

Edit: Couple minutes later than michael :x

Edited April 21, 2015 by Fenolis

[RayLeblancArt]

when you import an OBJ you can go into the Geometry Context and MMB on any of the nodes (like the file node) and you will see a listing of the attributes - P, N and uv (if it exists)...

also you can switch the viewport to UV (spacebar + 5) to see the uv's

Thanks for the tip, I see from MMB they are called primitive groups in houdini. 

[Georgie]

I only use OBJ's to transfer geo from Maya to Hou so I can't help with Alembic unfortunately. Here's my 'workflow' for exporting geometry out of Maya in a way that makes it easy for me to deal with it in Houdini :

 

 

Basically I Mesh->Combine all pieces that I want to be in the same Group in Houdini.

 

Then in Houdini, I drop a File SOP and select my file (don't forget to tick OFF "Show sequences as one entry" if you're importing static geometry and not a sequence).

 

The result is this :

 

 

 

 

As you can see, the UV attribute is preserved and the geometry comes in with Groups. Each Group name corresponds to each Transform node in Maya when exporting.

 

//I imported the geometry in Maya to make the first screenshot and it added the file namespace "forHou" that I forgot to remove. Ignore the "forHou" part of the naming in the first screenshot.

 

To isolate a specific group you can use a Blast SOP :

 

 

 

And to assign a Material to a group you can use a Material SOP :

 

 

 

 

I've attached an archive with the geometry and the hip file in case you want to check it out.

 

Just as a side note - if you export geometry as an OBJ file out of Maya with those options, I guess I should mention that to bring it back in, you need to set your Import OBJ options (the option box) to Multiple Objects under File Type Specific Options dropdown.

 

 

 

So to sum it up - the way you deal with your geo in Houdini depends on the options you used to export it in the first place. I'm pretty sure it's the same with Alembic. Try different options, see what you get, find what works for you and be happy ! Houdini can be kind of confusing at first because you have the option of treating geometry as separate Transform nodes (like in Maya) or sticking everything in a single Geometry node (like a container). You can do the latter in Maya as well by Mesh - > Combe -ing everything in your scene but that would be quite annoying to deal with imo.

I've never used DAZ sadly so I can't offer any help there.

 

Regarding Zbrush - what is it that you're having issues with ?

 

You may also want to check out this really cool shader - http://www.orbolt.com/asset/_danylyon::PBR_layered_material . It's free for Non-Commercial Houdini

 

Cheers !

forOdForce.zip

[RayLeblancArt]

While it's true that Houdini and Maya/Blender are quite different in the way they handle, I've used Houdini for a while now (switched from Maya almost a year ago) and I very much prefer the flexibility it offers.

 

As for your confusion, Houdini does have groups and will bring in UVs from imported geometry (if they exist). You can create a Group node in the network view to see the different ways you can group objects (bounding box is usually the most convenient for me). You can check for existing groups in imported geometry by middle-mouse clicking the File node - this will also show if the geometry has UV attributes. If desired, you can append a Material node to test your shader. Use the Group parameter to call in the group you wish to apply the shader to. If you haven't yet created a shader but wish to view the UVs, you can use a UVQuickShade node for clarity.

 

Hope this helps!

 

Edit: Couple minutes later than michael :x

I guess it's kinda like that in all packages. I am not really an expert at maya, but I can do basic stuff in it, problem is my maya is old, and can't afford to buy current maya. I figured I should start looking at more affordable solutions like blender, just recently found houdini. I am having some good fun in it so far, but it is pretty complicated. I love the idea of being able to make your own procedural tools though, one of the most attractive things to me really. Then I started watching tutorials on VFX and wow. I guess I really need to learn to crawl before I can run, so back to the basics tutorials for me.

[RayLeblancArt]

I only use OBJ's to transfer geo from Maya to Hou so I can't help with Alembic unfortunately. Here's my 'workflow' for exporting geometry out of Maya in a way that makes it easy for me to deal with it in Houdini :

Pictures are very helpful, thanks for taking the time to make that mini tutorial. I haven't even tried anything from zbrush as of yet, I guess I am just spoiled by that GoZ button. In the long run, it shouldn't be much of an issue, now that I am beginning to understand groups a bit better. I was thinking that if there wasn't a node for it, that it doesn't exist at all 

[Fenolis]

I was thinking that if there wasn't a node for it, that it doesn't exist at all 

 

Houdini is as much about creating your own tools to solve problems as it is about providing such tools. Some Houdini users create digital assets (reusable nodes) that let them work more efficiently by simplifying a complicated process (you don't have to create an entire set of nodes more than once!)