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View Full Version : Displacement and Subdivision order.



beachedsapper
09-26-2007, 12:36 PM
Perhaps I'm doing something wrong but why can't I have an object subpatched after displacement? I have a subpatch model with nodal displacements in Layout. If I leave the subdivision order set to first, the model is subpatched and then displaced. This can lead to sharp edges in the object which I find undesirable. Setting the subdivision order to occur after the displacement basically kills the displacement. Any ideas?

Surrealist.
09-26-2007, 02:31 PM
I had got this from NT tech support a while back for another problem. I think what you are experiencing is related to having to adjust the displacement order in two places.


The solution is to set the subdivision order to "After Motion", and the
bump displacement order to "Before World Displacement" so that it is
still done after the subdivision.


If these settings don't work try to experiment with the settings in both places (Geometry Tab and the Displacement Tab - near the enable bump button).

beachedsapper
09-27-2007, 09:54 AM
Thanks for the help. I've tried every combination of settings on those two tabs and it still doesnt do what I want. I can get one of two results. The object is subdivided and then displaced leading to sharp and jagged edges or the object is subdivided after the displacement which is pretty much killing the effect of the displacement entirely. I consider it a serious short coming if i can't displace my geometry and then subdivide the resulting mesh so its nice and smooth.

pooby
09-27-2007, 11:23 AM
What's happening is that it IS displacing the points, it's just that your base cage doesn't have many points to displace, so the effect is not coming across.
What people usually do is to subdivide earlier than displacement then up the level of subdivision so it will smooth out. Sometimes up to about level 30 or so.
What LW SHOULD be able to do (but can't) is to subdivide between displacements, so you could subdivide say to level 10, then displace, then subdivide again.

Surrealist.
09-27-2007, 11:40 AM
Right, that's the other angle. If you are getting displacement but it is jaggy it could be that you don't have it subdivided enough.

For additional information also check my tutorial. At at the beginning I go into the math of subdivision levels between Subpatch and CC. It makes a big difference how your model is subpatched as to what level to set it too.