# PP2014 render (smoothing?) artefacts on a morphed prop

• @bantha Just double checked 'degenerate triangle' - means all three vertices are colinear. Depending on which way Poser splits the quads (as Caisson mentioned) around the notch/nick into tris the triangles there are several close calls - BDE, ABC and BCD on the attached screenshot

"I would try it in a way that the edges do not cross:" the vertices/edges in the second column (orange in the screenshot below) are intended to remain vertical and colinear as they are the edge of the 'sharp bit' (technical term). Pulling the vertices from the sharp edge back past them was the only way I found to make the notch and (a) keep this vertical line, and (b) avoid coincident vertices, and (c) avoid quads with internal angles greater than 180°.
Your example (the green screenshot in your post) is an approach I didn't of, moving the central vertex to the side, so I may give that a try. The bottom face on the inside of the notch could end up non-planar (as it appears to be on your screenshot), and it would be easy to get interior angles of quads on the vertical surface greater than 180°.But forewarned is forearmed ! :o)

• This post is deleted!

• @caisson All the quads are planar to best of my knowledge, but there's always rounding errors. Bantha's comment about degenerate triangles is interesting and fits your comment about using a few triangles - maybe if I manually triangulate the specific problem quads to avoid the potential near-degenerate triangles ?

• Test 3 - Manually triangulating the potential problem quads in the base mesh doesn't seem to help.
(The morphed lower notch still gets those long thin triangles that Poser doesn't like. But on the unmorphed Obj B3 the long thin triangles are the same but the artefacts aren't there in the render. It seems to me that it's more to do with "that morph is a big change in the geo" (as caisson said, with the specific word highlighted by me). Maybe something to do with parts of the smoothing being done in accordance with the base mesh paramaeters ? (just a wild guess)

Edit:just confirmed same render artefacts in PP2014

• Removing smoothing and setting crease angle nice and low to 5 (started with test 3 scene with the manually triangulated mesh and made the adjustment noted)

• Question: the Firefly renderer. The only references to it I can find are in relation to Poser. Was it developed specifically for Poser, or was it taken from somewhere?

• This is IIRC, I did not find a reference any more. Firefly was licensed from another company, but I do not remember the name. When I'm not mistaken it was Mac only before. But that was FireFly as in Poser 5, no idea how much it still behaves like the original beast.

What happens with the morph dialed in at 0.9? When do the artifacts start?

• @bantha Up to 0.5 they're not really noticeable.

• I've been slogging away at this, trying to get to the root of the problem.
Artefacts show up on a simple OBJ (no MTs) in the preview pane with smoothing disabled.
If I reduce the crease angle from default 80 I find a value below which a particular artefact will disappear.
The artefact covers the whole of the face adjacent to the edge inquestion, although the lighting setup often makes it appear as if it's only one triangular half of the quad.
Adding a control edge close to the problem edge limits the artefact to the face between the edge and control edge.

• Yep, it needs control edges. This is just a quick test slapping in a couple of extra edge loops, but I think that's nailed the culprit and a possible solution/workaround:

I may have to rethink the modelling of the notches to get better control edges.

• But of course those control edges will also restrict the curvature of the surface to the area between the edge and the control edge.

And I've also got the sharp edge above the notch (red arrow) breaking open when I render with Smooth Polys.Reminds me of this https://forum.smithmicro.com/topic/746/why-does-this-mesh-split-on-one-edge-with-smooth-polys-pp2014?page=1
(Edit: but that red arrow is pointing to the old lower notch,which I didn'tfix with control edges! The problems probably still in the upper notch but restricted tothe control edge and thus too small to see)

• @3dcheapskate aRtBee researched the history of the the plugins including firefly in his Missing Manuals page and it is very interesting reading here:

http://www.book.artbeeweb.nl/dynamics-iv-2-poser-features-in-perspective/