Any limits in SDK for custom ops or can they do anything built-in ones can?

For example, can I build my own lagrangian fluid solver?

el_diablo
For example, can I build my own lagrangian fluid solver?

I don't know, can you? I sure couldn't…

There are no limits on what HDK ops can do. An HDK op is in all ways indistinguishable from a built-in op as far as Houdini is concerned.

Mark

So custom manipulators are a possibility? What about custom viewport drawing/openGL calls? As for the fluid solver, I thought about something simple/fast like Jos Stam's paper on fluid simulation for games.

Well, that's a very different question. Custom ops can do whatever built-in ops can do. The HDK provides hooks for creating custom OPs of any type. However the HDK doesn't provides hooks to access _every_ part of the software. In fact, aside from creating custom OPs, there are very few ways to hook into Houdini with the HDK. Custom manipulators are not possible. However custom viewport drawing code is possible by subclassing from GR_RenderHook (some examples are in the HDK under samples/GR).

Mark