In Houdini, is there something similar to XSI's “Subdivisions” settings in the Geometry approximation property?
I miss the + and - keys!!!
I created a torus and when I go to its parameters, I can only see the base subdivision. It does not seem “interactive” as in Softimage… :shock:

You can do that on object level, rendertab>Display As> Subdivision

Two ways:

SubdivideSop and choose the depth,

or if you use the Display As Subdivisions Surface under the Render tab, in the viewport Display Options, press ‘d’ over the viewport, the Tessellation/ Level Of Detail, this will change the global amount of refinement.

Thanks Sanostol
I managed to render as subdiv. But I can't find the option for the subdiv level.
This video does not tell it neither:
http://www.sidefx.com/index.php?option=com_content&task=view&id=751&Itemid=241 [sidefx.com]

Since mantra is a micropolygon renderer, you will have always perfectly subdivided surfaces, you don't need to worry about subdiv level.

The subdiv level in the viewport is tied to the viewport Display Options (hit ‘d’ to bring up the dialog) -> Geometry ->Level of Detail parameter.

There is definitely room for improvement in Houdini's workflow with subdivided geometry in the viewport. Please feel free to post any problems or suggestions.

Mark

Thanks guys for this great help!! 8)

Questions:
- To MartybNz: what's the advantage of this other method with SubdivideSop over the regular one?
- To Buki: really? Are you speaking about the rendering? Even if my subdivided object is set to level 1, it will render always perfectly, like a nurbs object?
- To Mtucker : thanks for asking. I think the way to increase and decrease subdiv level in XSI is great. Just hit the + and - keys on the numpad several time to lower or increase the subdiv level, in both the OGL view and the rendering. This is very nice when you're modelling on a low polygon count but still want to check how it will look and render. It's very fast. Softimage modellers use to hit these 2 keys very often. 8)

See you soon my friends,
-G

SubdivideSop gives you different algorithms to choose from, which is very nice - test it with a Box and select a polygon and use polyExtrueSop - the Houdini Catnull-Clark will work perfectly whilst the one you set at Scene level will lose the Subdivision whilst there are over lapping points.

The SubdivideSop is also changing the geometry, so you can edit the post subdivided surface whilst the one at Scene level is always working at the very end of the chain.

Thanks for the info, I have tried the Subdivide Sop and it works well. BTW why are there 2 inputs?
Also, another question: what if I want to put the Subdivide Sop on a whole hierarchy? I have an imported Alambic archive which top node is “alembicarchive1”, how can I put the same subdiv settings for all the hierarchy?
In Softimage it's easy to put a geometry approximation property on a whole hierarchy or group, but what's the equivalent workflow in Houdini?
Thanks a lot,
-G

I haven't tested the Alembic setup. With normal geo you could subnet the geo and append a SubdivideSop to the subnet, then just work on the geo inside the subnet. You would open two viewer panes and lock one to the subnet and one to the subdivide view, so you can see the subdivided and work on the pre-subdivied.

Similarly you could use a object merge in a geo node that you append a subdivideSop, then open a viewer for editing the original mesh and a viewer to see the scene subdivided level.

The second SubdivideSop input is for creasing; you can pipe in the same geo but delete the points you don't wont to crease. Alternatively you can avoid that second plug and just add a CreaseSop for the edges you want to be creased.

Thanks a lot MartybNz for your help.

“Subnet the geo”? Seems simple when you write it 8) but as I'm a total newbie I'm swiming in confusion. :?

I have tried adding an empty subnetwork Inside the “alembicarchive1” parent and then cut and paste things Inside the subnetwork, but it doesn't seem to work. It seems I have only 4 slots, and then, when I paste polygonal objects Inside, their whole hierarchy are pasted too.

I need a newbie tutorial about that. It should be simple: apply a unique Subdivide Sop to many objects in a multi-level hierarchy. just like a group in Soft!! :shock: Anyone knows a tutorial or video that could help??
Thanks
-G

No worries - it's pretty simple:

Subnets put the nodes down one directory level - remember Houdini is a file structure. In the screengrab you can see that on the left Tree View panel, with the subdivide sitting one level higher than the ‘box’ and it's polyextrudes.

To subnet nodes, select them in the NetworkEditor and press Shift key and ‘c’ key. The ‘open cardboard box’ icon at the top of the Network View also does this.

In the screen shot the two viewports are locked by the ‘pin’ icon at the top, left to a box modelling, and, right to subdivided node.

hey MartybNz
Thanks a lot for your patience and screenshot + sample scene.

First, according to your explanation, I'm not sure we're speaking of the same thing. BTW are you familiar with XSI? Here is a screenshot so I am sure we're on the same topic. It shows a Softimage scene that I'm trying to re-create in Houdini.
As you can see there is the scene root which is the top parent in the scen.
Under the scene root are several models. And Under each of these models are polygonal objects such as “plate_Fr”.
Another child of the scene root is the group “GroupGeoApprox” in which I have gathered all the scene's polygonal objects. On the group I applied a Geometry Approximation property that contains the subdivision values.
All polygon objects in the group inherit the Geometry Approximation property.

So now let's go back to your example scene.
I guess Houdini's equivalent to the scene root is the “Obj” node.
So first question, why is the “subnet_Polygon_model_in_here” a child to the “box_object1”? As it will ultimately contain several objects, it should be child to the “Obj” node…
Second question : I can't drag and drop the “subnet_Polygon_model_in_here” onto the “Obj” node?
Third question : I have tried to create a sphere as a child of the “Obj” node. I can cut it, but when I enter Inside the “subnet_Polygon_model_in_here”, I can't paste it.

So I'm pretty sure I'm missing the right workflow here… :?

Cool - no XSI experience here, only Softimage last century for a few days! It'll probably be best for someone else to translate all the Xsi concepts, but I'll try, though we are probably entering the area known as ‘the wall of confusion’ Make sure to check out Jordi's Xsi-Houdini guides! They are very popular.

The 3 questions seem to show a that Houdini has a different approach to Xsi, at least in this bit.

“subnet_Polygon_model_in_here” isn't a child of box- it's the opposite box is in the directory of “subnet_Polygon_model_in_here” - this the directory style structure of Houdini, not a parent-child relationship

The issue of dragging a subnet to the Obj is based on the same thing- the obj node is the base of the file system - it's effectively the root in a unix operating, but only for objects. Shader, renders, and the compositing network, also have their own areas, but, this too can be somewhat changed with Managers

Third question, that sphere is the object node - so you are effectively trying to copy that into the geometry area - which is not possible - you would go into the object node and copy the geometry node out and then paste that.

As far as I know Houdini doesn't use a ‘GroupGeoApprox’ type operator that Xsi does. It appears it affects anything you attach to it.

The subdivision you're seeking seems to be not a subdivideSop but a render time subdivision, that is easily achievable by the ‘Render Polydons As Subdivion (Mantra)’ checkbox on the Geometry node/Render tab. The viewport wont show the subd but Mantra will render it perfectly smooth.

It appears the Xsi ‘Explorer’ equivalent isn't the Tree view in Houdini, it is much closer to the List view set to Input/Output (see screengrab - this is available at the top of the Network View) I do remember every Xsi user looking for the same thing many months back. The Tree View is like a Os system file browser - you can also use the Textport to see this- try ‘ls’ to list the scene, ‘cd’ to change directory etc.

Hey Marty
Sorry for the HUGE delay. 8) Well, thanks for giving me a solution : “'Render Polydons As Subdivion (Mantra)' checkbox”. The problem is: I have many many boxes to check. So… I'll try to start a new thread about shared properties.
Thanks,
Gz