[Sidefx-houdini-list] Instancing in H11

Alex Czetwertynski alex at franktheplumber.com
Wed Sep 22 14:30:07 EDT 2010


It looks like it works fine as long as the points I'm instancing to have correct normals.
However it seems to me that the workflow has considerably changed in H11

For example there are no more obvious light shaders (such as VEX Distant Light for example), they are now relegated to an "old shader" section that you have to explicitly recall.
So it seems that you can actually instance actual lights (as in lights on the scene level).  You don't need to apply your intancepoint() expression to the light shader but to the actual light, and it seems that Sesi recommends you use the Instance object at Scene level (based on the manual).

Not sure if this is documented anywhere, but I'm trying to gather all the relevant info and hope to post it somewhere.

Thanks for that expression, it will definitely come in handy

Alex

On Sep 22, 2010, at 11:20 AM, jon parker wrote:

> Back in 9.5 I remember having to make an expression to disable the
> original light... something like this in the intensity parm:
> if(instancepoint() ==0, 0, 1)
> Jp
> 
> On Tuesday, September 21, 2010, Alex Czetwertynski
> <alex at franktheplumber.com> wrote:
>> Hmm, looks like I solved my own problem...For some reason I was convinced
>> the normals on the dome would have to point towards the object in the center
>> of it, but it looks like the opposite is the case.  Would love to understand
>> why, but in the mean time, it works :)
>> 
>> Thanks
>> Alex
>> 
>> 
>> On 9/21/10 6:29 PM, "Alex Czetwertynski" <alex at franktheplumber.com> wrote:
>> 
>>> Has something changed with regards to instancing in H11?
>>> 
>>> I'm following some very specific steps to create a light dome, and I can see
>>> this working in files created in earlier versions, but it will absolutely
>>> not work in H11....
>>> Maybe I'm doing something wrong.
>>> 
>>> I basically have a carved Nurbs sphere to which I added a Point SOP pointing
>>> the normals inwards.
>>> I then add the Instance folder to it and put my Light in the "Instance
>>> Object" field.
>>> I can see that the instancing works, but my original light is still clearly
>>> contributing to the scene.  If I turn it off, I don't get any light at all.
>>> I did turn of its display flag, but that does not seem to solve the problem
>>> 
>>> I tried doing the same thing but using an Instance object instead, as it is
>>> the approach the manual seems to recommend.  But that does not produce any
>>> result...
>>> 
>>> Here is my source file, if anybody wants to take a look.  If you turn off
>>> the Instance1 and turn on the Dome you will see the two objects being used
>>> for instancing.
>>> 
>>> http://christinerenee.net/alex/LightDomeHDA_build_2c.hipnc.zip
>>> 
>>> Thanks!
>>> Alex
>>> 
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