Convert imported geometry to mesh

[Mzigaib]

I have a geometry imported from Maya and I would like to convert it to a single mesh.

I've read in the manual the requirements to convert it, it has to be 4x4 polygons they have to share the coincident points, the only thing that I don´t know how to check or fix is the arrangement of the polygons "as n rows by n columns" as the manual says, how can I do that?

thanks.

[Jim M]

Dont you just use a file sop with a convert sop after, set to quads?

[Mzigaib]

Thanks for the feedback.

I didn't have to, it´s already quads.

What I really want to know it´s how I could reorder the the construction of the rows and columns of a imported mesh in a way that would be able to convert to a single parametric mesh.

I hope I could explain it right.

[mangi]

Hi there Mzigaib.

I do alot of exporting from 3d applications.

It´s kind of hard to see exactly what you are after.

can you put up a sililar hip here , not your original work . Just something basic and maybe I can help you out.

cheers mangic

[edward]

Why do you want to convert it to a mesh? Just keep it as polygons.

[Mzigaib]

Thanks again for the help.

I am trying to convert my imported obj to a single mesh so I can work with its parametric surface like using the carve sop to extract curves from it, the problem is that the obj doesn't come with the rows and columns ordered I would like to know how to fix it.

I hope you can understand through the pics, I am using the carve on both objects but only the one the were created in Houdini works right on the conversion to mesh and carving because it's rows and cols correct order.

I just hope that I could explain it right

Edited August 20, 2010 by Mzigaib

[mangi]

Hi Mzigaib.

Well I asked you for a hip. So I could see exactly what type of geometry we are looking into . but any way,

seeing the snapshot you sent, maybe what you may need to use is a fuze SOP

here is a snapshot.

mangic

[Mzigaib]

Thanks for the help Mangi.

But just using the fuse doesn't help to change the way that the imported object was created, if I just fuse it the primitives still carries the messed parametric UV from it´s creation, what I am trying to figure it out is a way reorder it´s parametric UV information or try to order procedurally it´s rows and columns in a way that all the quads connects continuously like a grid so that way when I convert it to a mesh or a nurbs surface I could get a whole surface and not a bunch of them.

But until now the only way I can see to do that is to recreate the model or parts of the model from the imported model with a correct parametric surface, the only problem is that I don't know how to transfer the animation from the messed up model to the correct new model.

I know it´s seems a lot just to get a surface conversion, but with that I could extract points and splines from it´s surface procedurally from a animated mesh coming from another 3D package which could help me a lot to explore some surface operations.

If you or anyone could understand what I am trying to achieve and have an idea I really would like to hear it.

Anyway thanks for the help and keep the ideas coming.

[mangi]

Hi Mzigaib,

Well I wish you good luck , anyway these methods that you are trying for a specific purpose , some how alway will

find there whay , as long as you keep on trying ...

cheer

mangi

[Netvudu]

I will throw in the Sort SOP just in case you have not looked at the more obvious solution...

[Mzigaib]

Yes, sort SOP could work, but I can´t find a way to make it sort the rows and columns continuously over the entire surface.

Any ideas would be welcome.

Edited August 23, 2010 by Mzigaib

[edward]

Are you sure you have some geometry is *exactly* representable as a mesh? ie. used as a NURBS control mesh. Even if you have such a situation, the difficulty will depend on the geometry you have.

[Mzigaib]

Yes I agree, In my case is that geometry that looks like a chicken wing, actually it is a bird wing, but I can easily reconstruct that particular geometry as a mesh on Houdini because it´s is a simple one, I am trying several methods to see which one is the most procedural and practical, the problem is that if the geometry is a little more complicated like the hole bird.

I am trying to get my meshes doing it by separate parts because I don need it to be as a hole I just need it to do some surface operations like extract some 2d parametric curves from it.

Another problem is that if I have reconstructed the geometry on Houdini how would be the workflow to transfer the deformation from the old mesh to this one, since the topologies are different I didn't figure out it yet.

Edited August 24, 2010 by Mzigaib

[edward]

Another problem is that if I have reconstructed the geometry on Houdini how would be the workflow to transfer the deformation from the old mesh to this one, since the topologies are different I didn't figure out it yet.

Use the AttribTransfer SOP and transfer a point index attribute. Then you can use it as a lookup between the deformed and your reconstructed geometry. This is assuming that your deforming geometry maintains the same topology throughout.

[Mzigaib]

If I want to do this with a reconstructed geometry the point index will differ.

[exu]

Thanks for the help Mangi.

But just using the fuse doesn't help to change the way that the imported object was created, if I just fuse it the primitives still carries the messed parametric UV from it´s creation, what I am trying to figure it out is a way reorder it´s parametric UV information or try to order procedurally it´s rows and columns in a way that all the quads connects continuously like a grid so that way when I convert it to a mesh or a nurbs surface I could get a whole surface and not a bunch of them.

But until now the only way I can see to do that is to recreate the model or parts of the model from the imported model with a correct parametric surface, the only problem is that I don't know how to transfer the animation from the messed up model to the correct new model.

I know it´s seems a lot just to get a surface conversion, but with that I could extract points and splines from it´s surface procedurally from a animated mesh coming from another 3D package which could help me a lot to explore some surface operations.

If you or anyone could understand what I am trying to achieve and have an idea I really would like to hear it.

Anyway thanks for the help and keep the ideas coming.

Hi Michel, you can use a group sop (with selected edges), sort the point number, convert it into a nurbs curves, and use skin to recreate a new parametric surface.

it's not fancy, and can be tedious, i know, but can be done.

cheers!

[Mzigaib]

Hi Michel, you can use a group sop (with selected edges), sort the point number, convert it into a nurbs curves, and use skin to recreate a new parametric surface.

it's not fancy, and can be tedious, i know, but can be done.

cheers!

Thank you very much for the idea for sure I´ll use that.

It´s really very hard to find a easy way to to do it directly, I came to the conclusion that sometimes the best way is to reconstruct the geometry itself, by like I already said the problem is that if the old mesh has animation I didn't find yet a way to transfer back the animation to the new geometry.

Anyway thanks again for the help.

[anim]

...

like I already said the problem is that if the old mesh has animation I didn't find yet a way to transfer back the animation to the new geometry.

...

let's assume that you've fixed the geometry and that fixing means just recreating the geometry with the same topology but sorted points

then you can use Match Topology SOP to fix the point order on animated geometry based on your fixed one