[x3d-public] 3D wrong visualization

[Bederov, Sergey]

Hello Cris and all,

Apparently X3DOM is having problems rendering large non-convex polygons, even if convex=“false”. Try triangulating the red polygon or separating it into smaller pieces.

A note to X3DOM developers. In the source code I have found the following line:

while(linklist.length >= 3  && count < 15) {

Apparently the “15” was added to avoid infinite recursion. In fact, it is limiting the number of “ears” clipped from the non-convex polygon. If a polygon is too complex, the algorithm tessellates a number of “ears” and then stops, leaving the remaining “ears” and the interior of the polygon empty. Increasing this value to 30 renders Cris’s polygon correctly. Anyway, I think it’s not a good solution because the polygons can have arbitrary complexity. Probably a different mechanism of detecting infinite recursion should be used?


                                                                                          Sergey Bederov


From: x3d-public [mailto:x3d-public-bounces at web3d.org] On Behalf Of Roy Walmsley
Sent: Wednesday, December 02, 2015 6:23 PM
To: 'Cris Lacumba'; 'x3dom mlist'; x3d-public at web3d.org
Subject: Re: [x3d-public] 3D wrong visualization

Cris,

I don’t know the answer, but I can suggest some questions.

Are your polygons being drawn on both sides? When you look at the X3DOM visualization, are the polygons being drawn on the other side?

How are you specifying the polygons in your model? Are you able to supply a listing of the model?

Regards,

Roy

From: x3d-public [mailto:x3d-public-bounces at web3d.org] On Behalf Of Cris Lacumba
Sent: 02 December 2015 11:44
To: x3dom mlist; x3d-public at web3d.org
Subject: [x3d-public] 3D wrong visualization

Hi all,
I'm visualizing some polygons in X3DOM and they are not correctly visualized.
In InstantReality (black background) is correctly visualized, however, in X3DOM I get an incorrect visualization.
Is there some solution?
Thanks in advance
Best regards

[Imágenes integradas 1][Imágenes integradas 2]
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