Cineversity

Two errors im getting on a render:

1. “could not generate tangents”
2. “update: could not execute Mesh geometry update for object ‘####’

what do these errors mean?

tried to google errors and looked into the forums but couldn’t find them

Windows 10
C4d 2023
Redshift 3.5.8
2 - 3090’s

Hi Sharon P.,

I have asked a colleague if those codes are public.

Perhaps I would check with the support.
https://www.maxon.net/en/support-center

Typically I would shut off half of the scene and see if the error persists; if yes, I shut off another half of what is left, etc.

You might have the problem area in no time, more often than not.

This should be then copied into a new scene and rendered. If reproducible, check the geometry of the use of a different material. I hope that helps.

If I get an OK and the data, I will share more.

All the best

Hiya Dr.S
Thanks for checking for me.
I searched the interwebs and couldn’t find the error messages.

Background:
This scene is a building and landscape for a new campus location. So i can’t share the file.
The buildling is tons of clones, that i am using fields to animate on the scale= -1. As the linear field moves up in Y space, the clones scale on.
On the polys that aren’t clones, I am using PolyFX with linear.  Since it is a project that is getting it’s camera data from AE, i have to render it on an alpha channel, and it’s an odd size. This render will be composited into 4K drone footage in AE. The reason it’s an odd size, is bec i am using the Undistort effect to offset the drone footage’s wide angle lens.So that undistort makes the file a bit larger than 4K so it can accomodate the warp, etc etc. You get it.

I’ll try what you suggest tomorrow and just see if something wacky got into the project.
This was a project created in 26 and i believe i had the errors there as well and when i opened it in 2023, they also popped up in the render display.

While it’s a LOT of clones, it’s pretty straightforward project.
When the error messages say “update: could not execute Mesh geometry update for object ‘####’....it has a number, and i would search the project and NEVER can find the number.  I have no idea where that number is generated. And there are LOTS of the error messages of both types.
The #### is different for each error message. It’s crazy! :D

Anyway, have a great weekend and i’ll give you an update next week.
The test renders seem pretty clean, i just hate getting render errors, bec i never know when that will bite me in the you know what after 24 hours of rendering (4k takes FOREVER!)

Sharon P.

Hi Sharon P.,

Please check with the support.
https://www.maxon.net/en/support-center

The earlier something that creates problems is cleared, the better your next project will run.

This is just a guess (or two of them), so I might be wrong:

1
If you set the scale to -0.99 instead of -1, do you get the same problem? With -1, the geometry is reduced to a “point-cluster” with no size; perhaps there is something.

2
Are there any XPresso-editor-based materials in the file? Going through all the past few weeks’ files and getting other feedback like yours makes me curious.

My best wishes for your project, and have a great weekend as well.

Hi Sharon,

Here is the first-hand information from a colleague: Please keep in mind that we have no file from you, so that is the best guess. He is typically spot on.

1.
Tangents are needed for bump mapping, normal mapping, anisotropy, and displacement; usually, the core tries to figure it out without but in some cases, they need to be pre-computed, and the plugin provides those. You compute the tangents from the UVs, and if there are no proper UVs, you cannot have proper tangents.
2.
The mesh geometry update might come from trying to evaluate a mesh that might not exist or not being properly generated/updated by c4d or even empty (in a simulation on the first frames, for instance), even missing data from an alembic file ...

All the best