[Sidefx-houdini-list] New Lighting Tutorial at www.sidefx.com

Robert Magee rmagee at sidefx.com
Tue Jan 17 12:30:41 EST 2006

Jean-Claude Nouchy wrote:

> Robert Magee wrote:
>> Good question. The models have all been designed to render as 
>> subdivision surface models. The option for this is found on the 
>> Render tab of each object. The object nodes can be found inside the 
>> digital asset subnetworks. By setting the "Geometry" parameter to 
>> "Polygons as Subdivision Surfaces" the low resolution model is 
>> subdivided by the renderer at a micropolygon level. This means that 
>> you don't have to tesselate the model or worry about breaking it down 
>> because it will be smooth no matter how close you get to it.
>> This is better than using a subdivide SOP which just tesselates the 
>> model into smaller polygons. Often I will use a subdivide SOP to 
>> preview the subdivide then set the render flag on the low res 
>> geometry and use the object level setting to get the best quality 
>> results.
>> Robert
> Thanks a lot Robert.. wow now that's cool..
> ok.. I have another question then.. about takes...
> I'm playing around with take from which i'm "including in take" some 
> parameters like sufaces colors.. and so on.. but on some shaders (like 
> the "filmcan6" (by CTRL+LMB click) ).. when i try to include the 
> Diffuse color (which in this case is a sort of blue) instead of giving 
> me free sliders to choose color it links such channels to 
> ch("../../vmetal1_diffr") (and blue and green) .. while on the table 
> this doesnt happens).

I assume that you are diving down to work with shader inside the filmcan 
digital asset. This is not necessary because on the filmcan asset itself 
there is a shading tab that has parameters such as vmetal1_diffr. It's 
"pretty" name is Metal Color but if you let you cursor hover over the 
parameter name you will see that it is vmetal1_diffr. This is the 
parameter that you should be including in the take. It is driving the 
parameter on the shader inside.

> and related to this.. where ch("../../vmetal1_diffr") points at? i 
> dont see any "vmetal1" vex shaders actually from the SOP network .. 
> but i might be confused and looked at wrong place.. dunno.

When you look at the ch("../../vmetal1_diffr") expression on the shader 
parameter, you are seeing a channel reference to the digital asset's 
user interface. This is how high level controls are set up for digital 
assets. Since the artist wanted their to be some shading control at the 
top level of the asset these references were set up to the high level 

> Hope i've been clear enought.. my english sucks sometimes :)
> and at last.. I dont get why if I change the reflection color (of same 
> materials for examples but on the table as well) this dont makes any 
> changes... i tried a bright red but i see no reflections...

I am not sure about this one. I will see if someone else can add more 
information on this one.

> cheers and thanks a lot for the fast support.

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