Hidden objects increase render time when Rendering to picture viewer

[zachary.mineo]

I was attempting to optimize my scene and it seems Arnold still exports hidden objects when rendering to picture viewer BUT not when exporting ass files.

Picture viewer Render with hidden geo:

00:00:15 17912MB         | scene creation time          0:11.94    machine utilization (0.14%) 
00:00:15 17912MB         |  plugin loading              0:00.49 
00:00:15 17912MB         |  unaccounted                 0:11.44 

Picture viewer Render with no geo:

00:00:04 17868MB         | scene creation time          0:00.58    machine utilization (1.21%) 
00:00:04 17868MB         |  plugin loading              0:00.48 
00:00:04 17868MB         |  unaccounted                 0:00.09 

Is this a limitation of cinema or is this something that could be change to behave in a similar way that .ass files exports handle hidden objects.

When I export .ass files from C4D it does not behave in the same way. Hidden geo will not be exported. This only happens when rendering straight to the picture viewer.

Related post about export .ass files in Maya with hidden objects.

[Stephen.Blair]

Can you post the full logs?

And how do you hide these objects?

[zachary.mineo]

Here they are. I turned off the parent null. Which makes me wonder if I should turn off all the objects individually. Let me try that.

arnold_Hidden_geo.txt

arnold_No_geo.txt

[zachary.mineo]

Turning off all the objects in the hierarchy did not effect it. It still seems to be exporting the hidden geometry

[Stephen.Blair]

In the hidden_geo, all the extra time is here:

00:00:00 17730MB         | loaded 13 plugins from 2 lib(s) in 0:00.00
00:00:11 17706MB         | 
00:00:11 17706MB         | authorizing with license manager: user ...
00:00:11 17706MB         | [user] authorized user "infoZZVT9"
00:00:11 17706MB         | [user] expiration date: 2022-07-13T19:59:59-04:00

That looks like licensing time, because not much else happens between "loading 13 plugins" and the license authorization.

Both logs show about the same amount of geometry being rendered. 1862696 polymeshes vs 1859560

[Stephen.Blair]

In hidden_geo, we have 4 polymesh and lots of shaders, so the geo is not hidden:

| there are 1 light and 6 objects:
...
|      26 standard_surface
|       1 bump2d
|       9 aov_write_float
|       4 color_correct
|       1 flakes
|      14 layer_shader
|       1 mix_rgba
|      12 normal_map
|       1 ramp_float
|       6 ramp_rgb
|      38 triplanar
|       1 user_data_float
|       1 uv_transform
|       5 c4d_texture_tag
|       3 c4d_texture_tag_rgba
|       1 gaussian_filter
|       4 polymesh
|       1 procedural
|       1 list_aggregate
|       1 driver_c4d_display

[Stephen.Blair]

So you have something like this?

[zachary.mineo]

Yes this is how I'm turning off the geo.

[peter.horvath6V6K3 · Accepted solution]

Picture Viewer and ASS export uses the same logic. If the object or parent is hidden (Visible in Render turned off), then it's not exported to Arnold.

What I'm seeing though, is that the shaders assigned to a hidden geometry are still exported. Does it make any difference, if you keep the geo but remove the shaders?

[zachary.mineo]

@ It looks like the issue was the shaders compiling. Even though the geometry is off Arnold must see that shaders are applied to geo and still compile them. I can send you the file if you'd like but it would have to be directly because of NDA.

[zachary.mineo]

We changed the verbosity level to debug and you can see it hang up on the shaders.mtd

Screenshot 2021-07-21 154810.png

[zachary.mineo]

Just saw this. Yeah we figured out it was the shaders. Is there anyway around this? its nice to have the speed of a procedural but have the original geo if we need to change something.

[peter.horvath6V6K3]

Don't think you can work around this, without changing it in the plugin code.

[Stephen.Blair]

It's not GPU and I don't see osl, why are the shaders taking so much time?

[zachary.mineo]

I have no idea. Do you have somewhere that I could send you the file I'm working with? It would have to send it privately because of NDA.

[Stephen.Blair]

@ You could send it to support @ arnoldrenderer . com