Can vertices and polygons display on OGL this way?

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48 posts
Joined: June 2013
Always wanted a OpenGL Toplogy valence display mode like above.

Is there a way to override OpenGL objects display like this?
Basically make a gradient with the number of vertices a vertex neighbors with and another with the number of vertices a polygon has.

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245 posts
Joined: Sept. 2011
I dont think you can do this by default, some scripting perhaps.

But if you dont have any scripting knowledge you could build a tool in Houdini which could group and color the components the way you like..
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325 posts
Joined: July 2007
Always wanted a OpenGL Toplogy valence display mode like above.


hi probiner ,

here i made a digital asset for you .

this is the ' most-not-procedural ' way of doing it , but even so it was easy to build and has basic control over its ‘GUI’ .

in order to have a more flexible digital asset , the best way to build it wd be to use multiparm controls with a lot of extra controls per group .

but even as it is ( my version ) you can add those extra features without the need to script .

additionally , i was incapable to color the points separately .

maybe some other forum member might help you ‘there’ or Hou's OGL might be incapable to do that .

keep in mind that my otl was build on H11 and i hope there is no prob for you if you are using a H12+ version .

+ , there is a test geometry file attached in case you do not have one for quick testing .


Attachments: (1.8 KB)
Clipboard-1.png (38.7 KB)
colorByVtxNum.otl (6.3 KB)

except the things that cannot be seen , nothing is like it seems .
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Joined: July 2005
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180 posts
Joined: June 2010
A Python version with Point support.

Much slower than the pure SOP and HDK approaches…difference may be largely unnoticeable unless you're feeding it to very dense geometry, and making changes upstream. It would certainly benefit a lot from inline CPP or Vex, but these are still on my rainy day list.

Add custom display options for attributes Ps (Point, text) and Ec (Prim, text) to get numbering.

Sadly, it seems sprites outside of POP networks can only be rendered in Mantra, so point representations are a no-go, outside the HDK at least…if anyone thinks I'm wrong about that, please let me know.

Also, you can only visualise Point or Prim coloring, not both at the same time, for obvious reasons!

Attached zip contains both test scene + .otl

It's not the most elegant coding, so feel free to point out the errors in my ways

Attachments: (36.8 KB)
topo_panel.jpg (91.1 KB)
topo_output.jpg (200.7 KB)

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