# Thread: PH in Polygons ?

1. ## PH in Polygons ?

Hello,

I'm trying to figure out how to correctly implement reading of Ph nodes in Polygons. Can anyone point me in the right direction ?

Thanks in advance !

2. the holes <ph> follow the polygon

they are part of.

3. Yes, I understand that part of it. What is a mystery to me is:

a) I've seen singular vertices in the

part before <ph>, how do you put a hole in a single vertex ? or am I just reading it wrong ?

b) Do we need to implement boolean calculations to actually convert to triangles ?

I figured there's got to be an easier way to parse this...

4. a) I've seen singular vertices in the

part before <ph>, how do you put a hole in a single vertex ? or am I just reading it wrong ?
That makes no sense. The

element should be consistent with the geometry that is in use. This seems like a bug that you should report to the right place

b) Do we need to implement boolean calculations to actually convert to triangles ?
There are several triangulation algorithms that can handle holes, such as http://www.cs.unc.edu/~dm/CODE/GEM/chapter.html

In the future we will provide such a triangulation algorithm as a conditioner in Refinery.

You can also select the triangulate option in all of the exporters.

5. Originally Posted by K-1
a) I've seen singular vertices in the

part before <ph>, how do you put a hole in a single vertex ? or am I just reading it wrong ?
The schema allows for a sequence of primitives that do not have holes, alternating with primitives that do have holes.

Code :
```<polygons>

<ph>

<h/>
</ph>
</polygons>```

Originally Posted by K-1
b) Do we need to implement boolean calculations to actually convert to triangles
No.

#### Posting Permissions

• You may not post new threads
• You may not post replies
• You may not post attachments
• You may not edit your posts
•