Hi there,

I have a very annoyed problem and I can't find a way for get out. I have the Alembic files from Maya and if I applied the remesh I lost the UV also I tried to transfer it a(after the promote from vertex to point) with the simple attribute, but didn't works.

How can I fix it?


thanks

ps.: I use H18.5.696 and I don't want use gamedev tool

I don't think there is a fix. That is state-of-the-art. Don't render the remeshed version, point deform the original using the remeshed version. Or re-apply your UVs after processing.

Can't you remesh in Maya and get perfect UVs from that DCC?

Enivob
I don't think there is a fix. That is state-of-the-art. Don't render the remeshed version, point deform the original using the remeshed version. Or re-apply your UVs after processing.

thanks for your reply. SO, I can't touch the UV because UV arrived from the model of Maya from another person and I can't touch it, I can only keep the same UV to my remesh models. I can't re-apply because coulb be a different respect the original.

Enivob
Can't you remesh in Maya and get perfect UVs from that DCC?

no, I can't use Maya for that.

I'm still looking around.

Matteo

MatEvil
Hi there,

I have a very annoyed problem and I can't find a way for get out. I have the Alembic files from Maya and if I applied the remesh I lost the UV also I tried to transfer it a(after the promote from vertex to point) with the simple attribute, but didn't works.

How can I fix it?


thanks

ps.: I use H18.5.696 and I don't want use gamedev tool

By "lost the UV" do you mean it didn't lose them but they just don't look very good? The remesh has an option to harden uv seams. As for distortion, the remesh does a pretty good job for uniformly distributed uvs, but it can only do so well using triangles to represent non-linear uv distortions. It certainly does not 'lose' the uv coordinates.

- remesh doesn't correct UVs to compensate for iterations, so the more iterations the more distorted uvs
- since you are using 18.5 the harden uv option may be missing, but you can easily use Group From Attribute Boundaries to create seams group from uv and use in Hard Edges Group Parm
- as for distortion you would have to sample the correct uv in wold space from original mesh per uv island

also hard edges would not be simplified in case your remesh is coarser than original mesh

- as a great alternative is Poly Reduce with Equalize edges weight quite high to make uniform triangles, that tends to keep the uvs pretty well and allows for simplifying boundaries also controlable using Vertex Attribute Seams weight slider
- you may want to subdivide and triangulate your geo before polyreduce if you are going for the same look remesh gives you

jsmack

MatEvil
Hi there,

I have a very annoyed problem and I can't find a way for get out. I have the Alembic files from Maya and if I applied the remesh I lost the UV also I tried to transfer it a(after the promote from vertex to point) with the simple attribute, but didn't works.

How can I fix it?


thanks

ps.: I use H18.5.696 and I don't want use gamedev tool

By "lost the UV" do you mean it didn't lose them but they just don't look very good? The remesh has an option to harden uv seams. As for distortion, the remesh does a pretty good job for uniformly distributed uvs, but it can only do so well using triangles to represent non-linear uv distortions. It certainly does not 'lose' the uv coordinates.

yep! "lost" I mean distort UV I try with the Hard edges option and maybe works (I should test on another complex Alembic).

thanks

tamte
- remesh doesn't correct UVs to compensate for iterations, so the more iterations the more distorted uvs
- since you are using 18.5 the harden uv option may be missing, but you can easily use Group From Attribute Boundaries to create seams group from uv and use in Hard Edges Group Parm
- as for distortion you would have to sample the correct uv in wold space from original mesh per uv island

also hard edges would not be simplified in case your remesh is coarser than original mesh

- as a great alternative is Poly Reduce with Equalize edges weight quite high to make uniform triangles, that tends to keep the uvs pretty well and allows for simplifying boundaries also controlable using Vertex Attribute Seams weight slider
- you may want to subdivide and triangulate your geo before polyreduce if you are going for the same look remesh gives you

tamte
may want to subdivide and triangulate your geo before p

Thanks Tom, I try to applied also the alternative way you tell but I don't see the UV, I continued to test.

MatEvil
I try to applied also the alternative way you tell but I don't see the UV, I continued to test.

- by triangulating I didnt mean Triangulate 2D node, just use regular Divide SOP at default settings
- do you see uvs on your mesh before Polyreduce? and are they vertex attribute?
- also you are talking about alembic are you feeding in packed alembic or unpacked geo and propery converted to Polygons? which is what you should do as most nodes will not modify geo of packed prims and many nodes don't work with polysoups
- your polyreduce is se to 100% so it will not reduce anything, nor anything to do with uvs, but also it would have kept them the same so the problem is most likely higher up

example file with some kind of source alembic may be better than screenshots

As an aside, can I ask why you need to remesh and render using that in the first place?
It doesn't make much sense. You'd generally only remesh to triangles for something like a vellum sim.
Which you would take the vellum sim and point deform the orginal mesh with good UVs, with your simmed one.

Can you tell us the reason for the remesh?

Also, this has nothing to do with Alembic, it's geometry 101 in general.


L

tamte

MatEvil
I try to applied also the alternative way you tell but I don't see the UV, I continued to test.

- by triangulating I didnt mean Triangulate 2D node, just use regular Divide SOP at default settings
- do you see uvs on your mesh before Polyreduce? and are they vertex attribute?
- also you are talking about alembic are you feeding in packed alembic or unpacked geo and propery converted to Polygons? which is what you should do as most nodes will not modify geo of packed prims and many nodes don't work with polysoups
- your polyreduce is se to 100% so it will not reduce anything, nor anything to do with uvs, but also it would have kept them the same so the problem is most likely higher up

example file with some kind of source alembic may be better than screenshots

ok, now I understand and found a way, now works.

Mat

tinyhawkus
As an aside, can I ask why you need to remesh and render using that in the first place?

no, you can't! lol I'm joking...

tinyhawkus
It doesn't make much sense. You'd generally only remesh to triangles for something like a vellum sim.
Which you would take the vellum sim and point deform the orginal mesh with good UVs, with your simmed one.

Can you tell us the reason for the remesh?

yes, for vellum simulation I build a setup for create some vellum sim and working with basic geometry (square, triangle geo) and with some custom shapes from another software like Maya and I need to create more points for do a good simulation and keep the UV from the original shape. If I'm working on the Triangular or Square shape (think to the flag or the sail of a ship) I can apply the UV then because you create it inside Houdini, but if you working with external shapes like Alembic from Maya, Blender, 3DS Max or Cinema 4D you should keep the UV from the original and for that I have that problem to not found a way for keep with the remesh.

When you finish the vellum simulation obviously you don't export the original alembic with the less points, but the new mesh with a more points and UV/attribute correctly.

Let me know if works for you or it's more incorrect way?

Matteo

You would never work this way. If the incoming mesh doesn't have enough resolution to deform to
your vellum sim, you simply subdivide the original mesh so it has enough resolution to deform how
you need.

The workflow for vellum on assets, is to always point deform the original by your simulation mesh.
Simply subdivide your original mesh will be all you need to do.

tinyhawkus
You would never work this way. If the incoming mesh doesn't have enough resolution to deform to
your vellum sim, you simply subdivide the original mesh so it has enough resolution to deform how
you need.

The workflow for vellum on assets, is to always point deform the original by your simulation mesh.
Simply subdivide your original mesh will be all you need to do.

ok, good to know I can delete all this part in my asset.

Thanks a lot