Question about Houdini's procedural nature

[thrasherstudios77]

What's up

I have been creating my first model in Houdini and have built quite a large network of SOPs. I was wondering if all of these SOPs are going to slow down my model once i start animating. In other 3D apps you push and tweak verts until you get the shape you want, and it is recognized by the app as one solid object, and even better you are usually able to delete history on that object to make it even easier to animate. But in Houdini every single step in the building of the model is recorded.

I have been making PolySplits and then using an edit SOP to rearrange the new vertices, but would it be better to make all my PolySplits first then use only one Edit SOP to rearrange them, so as to cut down on the number of Edit SOPs? Is there a operator in Houdini that will consolidate all the SOPs, like deleting history on the SOPs network so you only have the geometry and not the steps used to make it? Or is there nothing to really worry about each SOP doesn't take up that much memory.

I now this is a strange question but i need to now if i should change my modelling style to suit Houdini's procedural work flow.

[DaJuice]

It's not a strange question at all, I ran into the same issue a while ago.

Although I never animated my model, it got to the point where the file would take too long to load, and use up too much memory because my network was so big.

Instead of deleting the history (which is possible I think) you can just save out the geometry and start anew. What I do is, go into the Outputs panel and add a Geometry ROP. In the ROP parameters select your model and the SOP you want to "render" out (I usually choose the last edit SOP in my network). This allows you to export your model in various formats. bgeo is the best option for continuing work in Houdini, click the Render button and it will save the geometry in your Edit SOP as a bgeo file. Save your file end exit.

Start a new Houdini file and place a File SOP in your model object and point it to the bgeo you saved out. Voila, now you can continue to work on the model or animate it without the overhead of a huge network.

Hope that helps.

[stevenong]

...or you can Right-Click on the last SOP & select "Save Geometry..." from the pop-up.

Alternatively, you can lock the last SOP which cooks the whole network & saves the cooked geometry in it. This allows you an option to un-lock the locked SOP, edit the network before it, lock it again then continue working. The only caveat is the geometry is saved with the hip file so file size will increase.

Another method will be to Right-Click on the Geometry in the Viewport then select "Delete History". This locks the SOP like above but the network before the SOP will be deleted. Again, file size will increase with this method.

I hope the above helps!

Cheers!

steven

[thrasherstudios77]

Thank you for the replies

Well it seems I have many options, figures being this is Houdini. Ok so I now know how to make my model into a piece of geometry without the massive network behind the scenes, but what if I want to animate with my low poly model and have it effect my high res, subdivided model.

Would I cook the network to right before the Subdivide OP and then use something like Paste Copied Relative Refs from the low poly to the high translates;

(BTW I am not worried about the actual size of the Houdini scene file, just want the memory requirments of the geometry to go way down)

(lock it, or save geometry then reimport and then apply the subdivide OP)

[thrasherstudios77]

Thank you for the replies

Well it seems I have many options, figures being this is Houdini. Ok so I now know how to make my model into a piece of geometry without the massive network behind the scenes, but what if I want to animate with my low poly model and have it effect my high res, subdivided model.

1. Would I cook the network to right before the Subdivide OP (my high poly model) turn on the render flag for the Subdivide OP, while keeping the display flag on the SOP before the Subdivide. (I did try this and could not get it to work, but maybe I was doing it wrong and the theory is sound)

2. Do all of my animation with the low poly, then use a fetch OP in CHOPs and apply it to the high poly for rendering, the low and high poly models being different objects.

3. Yell "Houdini make it happen"... no I tried... it doesn't work

Stevenong- I am not worried about the actual size of the Houdini scene file, just want the memory requirments of the geometry to go way down. Of all the different methods you and DaJuice offered what is going to give my model the least resistance towards animation.

Benjammin

[Mcronin]

what if I want to animate with my low poly model and have it effect my high res, subdivided model.

All you have to do is rig the low poly model, and set it's OBJ render option tab to render "polygons as subdivision surfaces." Or, apply a subdivide SOP to the end of your network and set the render flag on it, while the display flag is on the low poly model's SOP. The, just rig the low poly model and it will render the shubdivided version.

[thekenny]

Agreed. Display your low poly model. It will perform better if you lock the SOP just above the DeformSOP. Or you could write out your captured geo to disk and fileSOP it into your file.

That will help you out more than anything. The RenderFlag can be on the SubdivideSOP and it will only cook during renders. I haven't used the render as SubD surface option but it does work. You shouldn't have to use Chops or separate low/high models (it was in your question).

Good luck

-k