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[Sidefx-houdini-list] Rest SOP - Procedural displacements
Monday, 10 April 2006 Mon, 10 Apr '06
I would really welcome this bit of "meta-data" as it would make things a lot clearer. At the moment it would nearly be better if you had to explicitly transform specific vectors manually to whatever space you want perhaps with the exception of N in shader contexts. Also, VOPs won't handle the vector [xyz] style of attribute which is a pain. Take the up vector, you can have 2 attributes up and up[xyz] living side by side in the same SOP at the same time. It can drive you a bit nuts!Oops! :-[ I see the Add Attribute SOP has a new "Vector Qualifier" button. Cooool... Thanks SESI!!
What kind of attribute would this "meta data" be? BTW, when it comes to shader space, I would prefer everything to be in "World" space myself rather than zeroed on the camera origin looking down the camera Z axis. These fundamental ways of handling different spaces should be documented in super big letters with flashing colours too.. L jlait at sidefx.com wrote: >On Thu, Apr 06, 2006 at 01:46:42PM -0400, Mario Marengo wrote: > >>On April 6, 2006 01:35 pm, Simon Barrick wrote: >> >>>Well, if not rest attributes, then some other attributes definetly used >>>to get stored as vectors and transformed when mantra got hold of them, I >>>distinctly remember having that issue. >>> >>Could very well be, and I have some similar memories of something >>like that... >>but I'm not sure of anything at this point :) >>Do you remember if the AttributeCreate SOP ever had a "3 floats" >>choice in the >>type menu? >> >>I would definitely like to know what's really going on with all >>this... SESI? >> > > As you have noticed, there are two ways to create the same thing >in SOPs. One is to have a "Vector" attribute and the other to have a >"Float" attribute of size 3. VOPs will only generate attributes of >the second type (float). > Some SOPs will transform Vector attributes in addition to the >point positions. This is the reason for the distinction - one wants >"v" (for velocity) to transform, but transforming "Cd" (for colour) >would be less sane. > The problems start to show up because the Vector attribute type is >considered different and incompatible to the Float attribute type >by Houdini's internals. This is why you can end up with two >attributes of the same name of the same apparent size when you mix the >two types. A goal is to one day merge the two types so the Vectorness >is just an extra bit of meta-data on the attribute rather than being >a type distinction. > ------------------------------------------------------------------------ _______________________________________________ Sidefx-houdini-list mailing list Sidefx-houdini-list at sidefx.com https://lists.sidefx.com:443/mailman/listinfo/sidefx-houdini-list