Get coordinates in 3D-Space

vvvv beta question
1

Hi vvvv guys!

I have two questions about 3D Geometry:

  1. I have a 3D-Box. I want to get the 8 xyz-coordinates of its 8 corners.
    I tried this via Mesh → Vertex Buffer. Here I get every corner 3 times.

I understand why, but is there a node which gives me every corner only 1 time? So that i have only 8 xyz-Values? Or is there a way to avoid doubles of the vertexbuffer coordinates?

  1. As I understand it, the coordinates i get via vertex buffer are only in object space. But I’d like to get the corner coordinates of my box after a transformation (i.e. in World Space). For example: “where in 3d Space is Point 1 of my box after I turned the box 20° to the left around the y-axis.”

Is ther a node for this?

Thank you!

2

Concerning 2:
Have a look at ApplyTransform (Transform)

3

Concerning 1:
if you only need it for a box you can setslice your own subpatch, or a more manual approach with pointeditor

4

concerning 2:
maybe this could help you:
I wanted to know the xy coords of xyz skeleton points from kinect, see the patch from sitd.
ask if you have question

Skeleton pipet SITD.v4p (13.9 kB)

5

Thanks for your fast replies!

Question 2 is solved, the ApplyTransform Node did it perfectly!

ggml, your approach to Question 1 works, thanks for that.
But i think it would be great to find a more comfortable way, which works also for more complex objects. Something where you connect any mesh and then it returns a list of every vertex (without doubles).

Does anyone have another idea?

6

Sift (Value) should do it

7

Sift (Value) is almost what i was looking for. I connect the vertexbuffer Positions to both the sift input and filter. It returns the sliceindex where a value appears for the first time.

Only Problem: It compares every single value and not triplets (xyz).
Any Idea how to do that?

Thanks.

8

Hi
I am not on Windows right now but since I don t remember any bin size pin on Sift you can probably just de-vectorize (vector 3d split), send to 3 sift nodes and compare the result but I do agree that there should be a more “geometrical” way to get what you want.
S.

9

Just to complete this thread:

Clean (Spreads BinSize) by @kalle does the Job concerning question 1.

Download here:
vvvv.org/tiki-download_file.php?fileId=1502