PDA

View Full Version : Render Subpatch Level Envelope = Partial Renderman Functionality



MH9
03-23-2004, 07:01 PM
I read that one of the abilities of Renderman is the ability to dynamically change the subpatch resolution of geometry as a camera gets closer to that object's surface, thus creating an always smooth surface while maintaining scene polygon efficiency.

I suppose that an envelope button for the "Render Subpatch Level" would allow an expression to be created for objects where the subpatch level will increase or decrease relative to camera proximity.

This could allow the always smooth look and create scene geometry efficiency at render time.

Additionally...

To have this envelope available for the Display Subpatch level would enable the same functionality for FPrime users.

If a toggle "ON" and "OFF" function were available for the Display Subpatch Level envelope, then one could navigate the scene with out the Display Subpatch Levels changing when the camera is moved, during scene set up, but then set to "ON" for FPrime render with out rewritting the expression each time you change from scene setup to FPrime render. [Currently to deactivate this envelope function, you would have to SHIFT+LMB the "E" button which would not just turn off the envelope, but erase all it's information. Maybe an ALT+LMB on the "E" would turn it only inactive rather than erasing it as well. That could be good for all envelopes.]

What would be even more user friendly would be a plugin, but, if an envelope for these two parameters gets this function to the user quicker, then i'd like to see the envelope feature first so that inovative people could have this function sooner.

Kind regards,
S9:Micah

Karmacop
03-23-2004, 07:07 PM
A subpatch level depending on camera distance, zoom etc would be cool, you should send the idea to [email protected]

However, because of the way Renderman renders it always splits ub the sub-d surfaces to be perfectly smooth (in the render anyway).

sailor
03-24-2004, 12:27 AM
of course it has nothin to do do with the renderman technology but there is already a LOD manager for subpatches in LW (since 6 if i remember well) should be in the plugins...this said i've never tested it.

sailor
03-24-2004, 12:29 AM
of course it has nothin to do do with the renderman technology but there is already a LOD manager for subpatches in LW (since 6 if i remember well) should be in the plugins...this said i've never tested it.


but even more spectacular than this is the fact that renderman renders nurbs trimmed surfaces...this is simply so revolutionary in the way you model that is like (lets find a comparison) being able to perfectly boolean subpatches...how cool is that for mechanical objects? ;)

MH9
03-24-2004, 11:31 AM
Nurbs trimmed surfaces... well that explains some modelling that i've seen lately. :)

I'll look for that LOD manager.

pixelinfected
03-26-2004, 05:39 PM
in lw 7 appair a new custom object plugin called
level of dectail mesh refinement
which allow you to setup a subdivision level linked to camera distance. but it start to work only from lw7.5 (but in lw7 beta worked).

this a crap implementation, be cause renderman work is deep different.

renderman subdivide surface with different algoritm of subdivision, with different resolution for different part, and interpolate surface in a smooth and fast way, be cause not subdivide poly, nurbs and subdivision by poly number, but id subdivide with a pixel precision, which alow to manage very low poly obj, and produce high poly like obj in render, with subpixel refinment, which allow fast and quality render with subpixel displament on simple obj at high resolution.

lw simply subdived poly in brutal and primitve way.
too distant from lw structure.

if you want to know more about renderman, you can download from pixar.doc the renderman info, doc, or siggraph paper about renderman technology.

have a nice day.