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View Full Version : Render time subsurface displacement mapping.



Ratteler
05-27-2004, 07:19 PM
I'm know I'm going to get boo's and hisses.... but Poser 5 and DAZ|Studio both have this.

It's like bump mapping on steriods. Lightwave has Displacemnt mapping, but not the kind that pretends to add geometry detail based on a B&W texture map.

Sure you crank your patch divisions through the roof, but that really bogs down the system since it's essentially subdivides you mesh automatically.

This would also be super useful for the gaming market where they use the same trick to give very low poly models a lot of percived detail.

bloontz
05-27-2004, 07:43 PM
I think you mean subpixel displacement.

Ratteler
05-27-2004, 08:24 PM
Originally posted by bloontz
I think you mean subpixel displacement.

LOL! Probably.

Mylenium
05-28-2004, 12:14 AM
Games use Normal mapping which does not create geometry. It's more like a smarter way of bump maps that properly applies smoothing and accounts for all light effects. You can do that already in LW using a free tool from Marvin Landis ( http://amber.rc.arizona.edu/lw/normalmaps.html ) Some games also use automatic LOD but that doesn't create geometry from textures either. The object is always derived from a high resolution mesh (= permanently optimized like in Quemloss or PolygonCruncher depending on the distance to camera). This is not doable at the moment as well as adaptive micro tesselation/ displacement. It would be desirable to have such tools, but would require a major rewrite of the renderer and the geometry core. Maybe they'll have it in v9 or 10.

Mylenium

Ratteler
05-28-2004, 09:13 AM
Hmmmm.... Good info.

I checked out that pluggin before, but it seem way more complicated than what i'm looking for.

In Poser and DAZ|Studio, the displacement mapping works like bump mapping, but has an effect simular to the "normal" mapping from that plugin in the end.

To get the same effect in LW witht hat plugin, I would need to apply a Bump stle Disp Map to a highly sub-D version of the object, freeze it into a massive polygonal object, then run the plugin to make the normal map for the new object.

While that would function... it's a lot more work that simply loading a bump map texture in the first place.

As you can probably guess... I'm not that technically inclined when it comes to what goes on behind the Lightwave (or any other 3D programs) interface.

But I do belive is such low end apps as Poser 5 and DAZ|Studio (Actually I think their Disp mapping is more of an artifact of the 3Dlight Render with hooks to it in their UI) can do it, Lightwave SHOULD be able to pull off the same trick some how.

I've see some amazing things done, those programs using this technique. Like very low res (nude) figures given more than enough clothing detail to act like background extras.

Mylenium
05-28-2004, 02:45 PM
Why do you call Poser Low end? Sure it's not very flexible for other things than figures, but it does this very well (Poser figures even appeared in one or the other form in Hollywood movies and I mean final versions, not just stand-ins). It's just different and very specialized and that also explains why it uses certain technologies/ techniques to achieve these effects. Basically all objects in Poser are treated like they are made up of "volumes" for each body part (polygons are only used to contain this volume and describe its shape) and thus have theoretically infinite resolution. In practice this means that the underlying engine would always assume it needs to re-calculate the surface and this makes it easy to factor in any displacement and other effects. Poser always was built around this paradigm and it would really be some task to get something like that in LW. Of course it also would be just as difficult to turn Poser into a perfect polygonal Modeler such as LW...

Mylenium

bloontz
05-28-2004, 03:00 PM
I believe Poser supports subpixel displacement through Firefly which is a port of Tempest, the Renderman compliant Reyes renderer from Pixels 3d.

wacom
05-28-2004, 04:04 PM
sub-pixel displacement is needed in 8.5. Ask anyone with Z-brush why.

bloontz
05-28-2004, 04:21 PM
Originally posted by wacom
sub-pixel displacement is needed in 8.5. Ask anyone with Z-brush why.

Proton has ZBrush so hopefully he will stress the need for this to the developers.

Ratteler
05-28-2004, 11:46 PM
Originally posted by Mylenium
Why do you call Poser Low end?
Mylenium

Mostly because it coded ratherly crappily and doesn't cost much.

I'm a big fan of what has been done with Poser, but feel it's owners have really shot themselves in the foot.

DAZ|Studio, (which is free, and who's developers are also big Lightwave fans) stands a much better of carrying the Poser torch.

The fact is that both their implementations of Displacment mapping are really just more coninving forms of bump mapping.

I've seem other Lightwave Render pluggins that alter change the image in far more complex ways. This shouldn't be rocket science. It's really just a kind of notch calculation at the edge of a bump map if you thing about it.

At any rate. That's my top LW Feature Request.:D