Hullo,

I was trying some learning exercises and ran into snags when trying to play with attributes. Simple stuff and a newbie point of view, but:

1) Primitive attributes in SOPs. Simply put, how do I set the value of a primitive attribute? You can modify values of arbitrary point attributes in a Point SOP, but not in Primitive SOP?
In my case I was trying to multiply “area” with clamped N. It was easy to circumvent by setting the alpha in Prim SOP to what I needed, or probably by promoting to point attrib and back, but it feels like there should be a way to just set the value of a primitive attribute directly. A “Custom” tab for Primitive SOP? Am I missing something obvious here?

2) Not that big, but accessing point attributes from a vopnet. I was trying to access a point attribute in a COP vopnet, and there is a primitive attribute node but no point attribute node. Perhaps it could be done via a point cloud, but for completeness' sake a point attribute node would seemslike a good idea. Unless I'm missing something again

eetu.

Now of course I get it to work just after posting..

For posterity, I write .geo to stdout.

Next, making the importer robust…

eetu.

Hullo,

I'm working on a lightwave/modo (.lwo) geometry importer, and I'm a bit unsure of how the GEOio mechanism works.

- Should the importer write to stdout, or should it write to stdout.bgeo? The text says stdout, but why then are the converters passed “stdout.bgeo” as a second argument?

- Can the importer write .geo or does it have to be .bgeo? Again the text says “.geo/.bgeo” but I'd like to be sure.

My commandline converter creates valid .geo, but I can't get it to work through GEOio - trying to narrow down the possible problems here

eetu.

Hello,

seems to me there's some grave problems with subdivision surfaces in the latest build.

New scene, drop down a box and a spotlight, tick ‘render polygons as subdivision surfaces’

9.1.155: a nice ball
9.1.156: nothing

eetu.

I haven't used 3delight or Maxwell with Houdini yet, but;

Freakish
Exactly where do i find the “HOUDINI_DEFAULT_RIB_RENDERER environment variable” to set it as above?

My computer -> properties -> advanced -> environment variables.

Freakish
Also is there a current plugin for Maxwell Render available?

Search for Maxwell toolkit in the Houdini Exchange. (in the menu above)
In fact with any luck it's on the exchange front page at the moment.

eetu.

pbowmar
What do you mean by point attributes of different dimensions? Just curious…

Pretty much what niko said, selection sets (0 dim), weight maps(1dim), UV maps (2dim), RGB and morph maps (3dim) and RGBA point maps (4dim).

I made a .geo loader for LW which tries to handle these, but proper support in the other direction would be super..

eetu.

Seconded!

(and with support for point attributes of different dimensions pretty please

eetu.

Yep, normals are smoothed over all points by default. For first aid put down a Facet SOP and tick the “Unique Points” box. That un-merges the points and the edges will look hard.

eetu.

According to the documentation, the lwo loader was made for lw 3.5 - which is more than a decade old

An updated one would be real nice, especially as lw objects have all kinds of per point attributes and such these days. It would be very nice to have them accessible in Houdini.

.. And that would add Modo-compatibility for free, too

eetu.

Try exporting .obj from lightwave, the obj loader in houdini is better.

eetu.

1) That is because the objects have smoothed normals. Put a facet SOP after the partition SOP, enable “Unique points”. (which leads to an additional question; is there a way for polygons to have independent normals without duplicating the points? vertices?)

2) In your fractured object DOP, change Collisions -> Surface -> Surface representation from “Points” to “Edges”

eetu.

Maybe someone who has managed to compile this for a current
Houdini build would care to share the compiled version? Pwetty Pwease?

I got the impression that it's doable but am too lazy/busy to try to tackle it
myself

eetu.