Realflow Alembic mesh smoothing. #50255

New Issue

Minne Danhieux · 2016-12-15T15:05:54+01:00

Minne Danhieux commented

2016-12-15 15:05:54 +01:00

Dear Kévin,

it's nice to see how smooth realflow meshes are working in Blender with alembic.
I ran into a weird problem... My smoothing on the mesh isn't working.

I tried everything I know about smoothing and normals... maybe I'm doing something wrong, or its broken somehow.
I marked it as a bug but it could also not be a bug.

I push smooth shade button.
Autosmooth is disabled
I checked custom split normal data, there is none.
I tried with Autosmooth on and different angles
No succes.
Also tried sub-d modifier and edgesplit and some combinations, but it stays flat shaded.

Here is the mesh sequence in alembic format. meshes.rar

WIN 7 64b B27.8a

Thx for looking into this.

Regards,

Minne

Dear Kévin, it's nice to see how smooth realflow meshes are working in Blender with alembic. I ran into a weird problem... My smoothing on the mesh isn't working.![smoothing_problem_alembic_realflow.JPG](https://archive.blender.org/developer/F418159/smoothing_problem_alembic_realflow.JPG) I tried everything I know about smoothing and normals... maybe I'm doing something wrong, or its broken somehow. I marked it as a bug but it could also not be a bug. - I push smooth shade button. - Autosmooth is disabled - I checked custom split normal data, there is none. - I tried with Autosmooth on and different angles - No succes. - Also tried sub-d modifier and edgesplit and some combinations, but it stays flat shaded. Here is the mesh sequence in alembic format. [meshes.rar](https://archive.blender.org/developer/F418162/meshes.rar) WIN 7 64b B27.8a Thx for looking into this. Regards, Minne

Kévin Dietrich was assigned by Minne Danhieux

2016-12-15 15:05:54 +01:00

Minne Danhieux commented

2016-12-15 15:05:54 +01:00

Changed status to: 'Open'

Minne Danhieux commented

2016-12-15 15:05:54 +01:00

Added subscriber: @MinneDanhieux

Kévin Dietrich commented

2016-12-16 00:52:13 +01:00

The issue probably comes from the fact that meshes are empty when importing Alembic objects and the data is generated by the modifier. For smooth normals to be applied through the modifier, it needs to be applied on the mesh before it gets fed through the modifier stack, but since meshes are empty before going through the modifiers, the smooth normal data can not be carried.

As a temporary solution, you could try to create a dummy object (like a cube), and add the Mesh Sequence Cache modifier to it, properly setting the cache file and the object path. Then smooth normals should work.

Normals in Alembic are a bit of a hassle since they can be stored in different ways, and it is not as straightforward to handle them on the Blender side as it seems (a lot depends on how other software output their normal data). Perhaps I could add a user setting to the modifier to tell to set smooth normals flag on the mesh's polygons?

In any case, I had to reinstall my OS, and I haven't yet reinstalled the Blender related stuff, let alone the compilers and general development stuff, so this will have to wait a bit before I can take action.

The issue probably comes from the fact that meshes are empty when importing Alembic objects and the data is generated by the modifier. For smooth normals to be applied through the modifier, it needs to be applied on the mesh before it gets fed through the modifier stack, but since meshes are empty before going through the modifiers, the smooth normal data can not be carried. As a temporary solution, you could try to create a dummy object (like a cube), and add the Mesh Sequence Cache modifier to it, properly setting the cache file and the object path. Then smooth normals should work. Normals in Alembic are a bit of a hassle since they can be stored in different ways, and it is not as straightforward to handle them on the Blender side as it seems (a lot depends on how other software output their normal data). Perhaps I could add a user setting to the modifier to tell to set smooth normals flag on the mesh's polygons? In any case, I had to reinstall my OS, and I haven't yet reinstalled the Blender related stuff, let alone the compilers and general development stuff, so this will have to wait a bit before I can take action.

Minne Danhieux commented

2016-12-16 11:24:01 +01:00

Thx for the clear explanation and more importantly: a working solution!

It would be nice to have the option flag for sure.

What about this : Importing the sequence with a mesh that is not empty? I'm guessing 1 triangle would do the trick.
When you create the "dummy mesh" you could add 1 triangle(or wathever is needed) before adding the modifier.
Dono if such a solution is acceptable design wise...

In any case thx again for the fast response and the "good enough for me" solution. :)

Thx for the clear explanation and more importantly: a working solution! It would be nice to have the option flag for sure. What about this : Importing the sequence with a mesh that is not empty? I'm guessing 1 triangle would do the trick. When you create the "dummy mesh" you could add 1 triangle(or wathever is needed) before adding the modifier. Dono if such a solution is acceptable design wise... In any case thx again for the fast response and the "good enough for me" solution. :)

Sybren A. Stüvel commented

2019-08-22 17:06:20 +02:00

Added subscriber: @dr.sybren

Sybren A. Stüvel commented

2019-08-22 17:06:20 +02:00

Changed status from 'Open' to: 'Resolved'

Sybren A. Stüvel closed this issue

2019-08-22 17:06:20 +02:00

Sybren A. Stüvel commented

2019-08-22 17:06:20 +02:00

This doesn't seem to be an issue in current Blender any more:

It probably was fixed in e9c149d911.

This doesn't seem to be an issue in current Blender any more: ![image.png](https://archive.blender.org/developer/F7687041/image.png) It probably was fixed in e9c149d911.

Sign in to join this conversation.

No Label

Download

What's New

Blender Studio

Manual

Developers Blog

Documentation

Benchmark

Blender Conference

Development Fund

One-time Donations

Realflow Alembic mesh smoothing. #50255