Author Topic: Deformable meshes - problem with .abc file geometry / [Blender/Keyshot]  (Read 5314 times)

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Offline Oskar_K

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Hello everyone,

Recently I found out the newest version of Keyshot has a feature I was waiting for as a standard - importing deformable meshes via alembic format. I tried basic animation using Blender and most recent available trial version of Keyshot. Everything works fine, and that is supercool except small problem with the imported geometry itself and the way it reflects the light. I tried two different scenes and the problem repeats only with variations of very basic cube with the Blender starting scene comes with.

Please find attached short animations as well as second's animation first frame rendered.

Is anyone able to figure out what is the reason of that effect? How to fix it?

Thank you,

Oskar


Offline DMerz III

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Re: Deformable meshes - problem with .abc file geometry / [Blender/Keyshot]
« Reply #1 on: February 07, 2018, 02:17:58 pm »
 :) very cool that you got the deform-able mesh to work, I've been wanting to test this with blender myself, but it keeps getting pushed.

As for the material, can you give some insight into what material you are trying to achieve, and what you have assigned at the moment? It looks pretty crazy...are you trying to map the green texture? Perhaps a screenshot of your material graph and or material tab will give some needed info.

Offline Oskar_K

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Re: Deformable meshes - problem with .abc file geometry / [Blender/Keyshot]
« Reply #2 on: February 07, 2018, 10:45:49 pm »
This happens with any material including starting diffuse one. Those above are some random from the library. In the physics simulation the cube is plastic matte black or so and bending animation includes some of painted materials.

Offline DMerz III

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Re: Deformable meshes - problem with .abc file geometry / [Blender/Keyshot]
« Reply #3 on: February 08, 2018, 07:43:41 am »
Hmm, strange, in Blender, did you apply a material or are the slots blank?

Just seems odd, there's what looks like transparency and labels, but you're saying those do not exist in the shader.


Offline Oskar_K

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Re: Deformable meshes - problem with .abc file geometry / [Blender/Keyshot]
« Reply #4 on: February 08, 2018, 07:58:19 am »
I didn't apply any material/texture in Blender (honestly I don't even know how to do that)

I will try to test it with different models as it seems to appear only with cuboid geometry (cone, ball, and "cloth" models are ok, the same with fluid I tested in other scene)

Offline Will Gibbons

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Re: Deformable meshes - problem with .abc file geometry / [Blender/Keyshot]
« Reply #5 on: February 08, 2018, 08:47:58 am »
Hey,

Good news, this is a simple fix, bad news, our importer doesn't seem to do this on its own every time. All that's happening is poor normal calculation. Be sure you look through all Blender's ABC export options to include everything you need to... smoothing and converting to triangles if you can.

Then, in KeyShot's import you want to check 'calculate normals', and if that doesn't work, right-click the item>edit geometry>calculate normals.

This is how I've experienced it.

Here are notes I made from what I found to work pretty well:

Alembic (.abc) (Animation)
- Specify Start/End frame
- Subsurface Modifier - Only uses Render Subdivs
- Apply Subsurf (Y)
- Use Subdivision Schema (Y)
- Normals (Y)
   KeyShot Import
        - Calculate Normals (Y)

Offline Oskar_K

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Re: Deformable meshes - problem with .abc file geometry / [Blender/Keyshot]
« Reply #6 on: February 08, 2018, 11:49:48 am »
Thank you Will for your reply.

Quote
Subsurface Modifier - Only uses Render Subdivs

I couldn't find it in the export settings in Blender. The other checkboxs I picked as you listed, nothing changed. What's more, regarding this particular imported part, I can't use "edit geometry" option.

Here you can see also the list of errors which pops up while importing .abc file. Each time I import alembic, some errors occurs. Would be also great to know what it means.

Does anyone have any other idea how to fix that?

Offline Oskar_K

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Re: Deformable meshes - problem with .abc file geometry / [Blender/Keyshot]
« Reply #7 on: February 08, 2018, 12:30:48 pm »
Some more tries with Subdivision Modifier added, there are some changes, but not exactly the way I'd wished...

Online hstokholm

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Re: Deformable meshes - problem with .abc file geometry / [Blender/Keyshot]
« Reply #8 on: February 09, 2018, 01:35:27 am »
If you are able to share the .abc file I will take a look. :)

Offline Oskar_K

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Re: Deformable meshes - problem with .abc file geometry / [Blender/Keyshot]
« Reply #9 on: February 09, 2018, 02:30:46 am »
Please find attached alembic files.

First one: standard export alembic settings
Second one: export alembic file settings according to Will's suggestion
Third one: export alembic file settings according to Will's suggestion and subdivision modfier added

Online hstokholm

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Re: Deformable meshes - problem with .abc file geometry / [Blender/Keyshot]
« Reply #10 on: February 09, 2018, 03:00:16 am »
Thanks. The issue is that something goes wrong with the normals when converting from quads to triangles in the importer. I will log this in our system.

A workaround until this is fixed is to triangulate the mesh in blender prior to the alembic export if this is possible.

Offline Oskar_K

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Re: Deformable meshes - problem with .abc file geometry / [Blender/Keyshot]
« Reply #11 on: February 19, 2018, 11:24:07 am »
Just in case anyone in the future is interested in the solution to that problem:

I exported alembic file from blender with standard settings. In geometry editor I applied "edit normals" with 1 degree angle and it works! Please see printscreens below.

Unfortunately, now I encoutered another problem. Is there any option to edit geometry of multiple parts with one action? I found it impossible and with the first project I wanted to do it was needed. Any input from you will be appreciated.

Offline mattjgerard

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Re: Deformable meshes - problem with .abc file geometry / [Blender/Keyshot]
« Reply #12 on: February 19, 2018, 11:28:48 am »
Is there any option to edit geometry of multiple parts with one action? I found it impossible and with the first project I wanted to do it was needed. Any input from you will be appreciated.

Not at this time. i was looking at this as well for some solutions for models coming over from Cinema 4d, where I wanted to recalculate normals for a large group of parts, but there is no way to batch that as of yet. i was going to look  into scripting it somehow, but have not yet explored that option, if its even possible.

I ended up working with the plugin dev and they were able to tweak the plugin so that under 90% of the times it comes in correctly now.

Offline DMerz III

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Re: Deformable meshes - problem with .abc file geometry / [Blender/Keyshot]
« Reply #13 on: February 19, 2018, 11:37:18 am »
hmm, interesting. Hey Oskar, did you by chance try the triangulate method which hstokholm mentioned above?
I know you can triangulate geometry through a modifier, but not sure if that is going to mess with your deformation.

Offline Oskar_K

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Re: Deformable meshes - problem with .abc file geometry / [Blender/Keyshot]
« Reply #14 on: February 19, 2018, 12:14:49 pm »
hmm, interesting. Hey Oskar, did you by chance try the triangulate method which hstokholm mentioned above?
I know you can triangulate geometry through a modifier, but not sure if that is going to mess with your deformation.


Thank you guys for your replies.

Yes, I did. One of those three cube was trianguled with Blender's modifier with no visible result (on the printscreen you can see result after editing geometry). As I am rather begginer user of blender I just did it with default settings, I'll do some reaserch in that field and try to explore possibilites inside Blender. That is very important for me, I am convienced that getting good results in deformable meshes animated in Blender and rendered in KS would revolute not only my workflow.