Houdini Wish List

[crunch]

Let me start this off from Jon's post
- Remove slashes from Houdini object names (replacing with underscores)
- Export of bounding box information for place-holders

I don't have the .mi specs in front of me right now, but if there's no way of specifying the bounds, perhaps a comment with an easily identifiable syntax could be used? Again, H9 is pretty flexible w.r.t. .mi generation, so it should be easy to add this as an optional feature.

I should be able to add both of these sometime next week to the H9 distribution if you want to take the plunge and try it out...

I'll edit this post when these features are in.

[bart]

If the slashes are to indicate hierarchy, would a greater than (>) sign work?

Re: bounding box syntax
In the object block:

box <minx> <miny> <minz> <maxx> <maxy> <maxz>

There is also a motion bounding box for the box at the end of a frame.

In addition to the on-line manual in Scene Entities>Objects, see the placeholder tips page for more examples of syntax for the bounding box, and more related to placeholders.

http://www.lamrug.org/resources/placeholdertips.html

[parker]

So I'm getting a nice list here already... these are from Andy Walker (can't find his login to the board...). I'd qualify that these requests are from using Houdini 8.

- Optional binary MI export
- more predictable scene fragment export... it looks like in version 8, camera data, options blocks and lights were getting exported every time.
- real 3d motion blur data from velocity attributes attached to objects

[parker]

Here's a better possible implementation of object renaming in MI's, by being able to tag an optional MI export name to the object itself instead of a global change, since usually we'd only be doing one object at a time anyways for placeholders. In any case I'd be hesitant to change the current method globally (from "/obj/thing") only to appease the way Maya handles object names... in my opinion Houdini's MI's generally are cleaner than Maya's and I wouldn't really want to monkey with a good thing

[crunch]

Tomorrow's build of Houdini9 should have two new features:

A new parameter (soho_safename) will cause all non-safe characters (alphanumeric and underscores) to be replaced with underscores ('_'). Alternatively, you can also alter the Python code and massage the names if you really want.

The safe name generation is a general feature for all output drivers, not just for .mi files. Though, currently it's a global setting (so it can't be applied on a per-object basis).

There's now a new parameter, mi_outputbox which will cause the "motion box" to be output for objects.

----

- Optional binary geometry should be pretty straight-forward as well. I'll have a look this afternoon.
- Fragment export is something that's a lacking a little bit in Houdini9 in general. Hopefully H9.1 will see a new archive generation process which will allow a finer control over which entities get dumped into fragment files.
- real 3d motion blur? If you turn on velocity motion blur, you should get true 3d motion vectors in the .mi file. Could you clarify please?

Thanks,

[crunch]

Again, in tomorrow's build:

The mi_binarygeometry parameter can be used to turn binary output of vectors on or off. It defaults to on.

In reading the reference, I was only able to find reference to vector data (enclosed in ``). But, there didn't seem to be a way to pack the vertex reference lists in a binary format. Is there a more compact representation available?

[parker]

Thanks for such fast changes! I'm checking in with Andy about the motion blur, should get a response from him at some point soon...

[Puppet]

I have some suggestions for mr in houdini...

1. Please support default value and range from mi file in mids utility. In current version all shader parameters have all zero values.

2. If shader have multiple type like:

apply material, shadow

shader will be putted to last category only (shadow). I suppose better will be if shader will be in both categories.

[parker]

Puppet / crunch:

Do either of you know if there is a way to use a shader in place of a scalar/color/vector value in SHOPS for mental ray in Houdini?