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Geometry Issues CPU vs GPU

Hello - I am experiencing a problem with an imported model of some city data I need for a client project. The model is large - real world scale 1:1. It's fine from a distance but when I zoom in to the areas I will need to produce renders the geometry appears with vertical shading artefacts - but only when using GPU mode, this happens in both real-time view and when rendering an image out. The model is relatively low poly count (<4M). The model is lit using the LA sky HDRI.


I have tried re-tessellating the model at 1.0 and this does not fix the issue. Can anyone at Luxion assist please? I can workaround by rendering on CPU but it would be useful to know why this is happening (e.g. is it geom, scale - GPU card specific?).


I have lots of issues with GPU mode - particularly with render queue (e.g. incorrect fuzz results). They still exist in v10


The model is large ~350Mb, happy to send to you.


(btw - I've pixelated part of the close up images to hide the object of this work which is confidential).


thanks


David



Hello David,

Thank you for contacting Luxion .
What are the specs of your computer?
  • Manufacturer (Dell, Toshiba, HP, etc..)
  • Windows/Mac OS version
  • Graphics Card model and driver version
  • Processor model
You can try updating you graphics card's drivers.
We recommend driver version 451.82 and up. We can not recommend drivers of version 450.xx and below as there are known issues in KeyShot with those drivers.
 
If that fails, please send us the scene as a .ksp file. You can remove the confidential model if you wish.

To save a ksp file:
  1. Open your scene.
  2. Go to File > Save Package.
  3. Name your file.
  4. Include Ticket number.

You may send it securely via our WeTransfer

 

Referencing your Ticket ID#:21224

 

Med Venlig Hilsen / Best Regards,

Erik Williams
Customer Support Specialist
Hello David,

Thank you for contacting Luxion .
We have not yet received the .ksp. Can you resend it?

To save a ksp file:
  1. Open your scene.
  2. Go to File > Save Package.
  3. Name your file.
  4. Include Ticket number.

You may send it securely via our WeTransfer

 

Referencing your Ticket ID#:21224

 

Med Venlig Hilsen / Best Regards,

Erik Williams
Customer Support Specialist

Hello. Just want to check if you have got the scene I sent via WeTransfer?


thanks


D

Hello David,

Thank you for contacting Luxion .
​Actually we have not yet received the file.
Can you give it one more try?
If this fails again I will send you my personal email address.

Let me know once you resend the scene.

Referencing your Ticket ID#:21224

 

Med Venlig Hilsen / Best Regards,

Erik Williams
Customer Support Specialist

OK resent again


D

So I had the chance to try a couple of things;


1. Editing tessellation does not fix this problem, nor normals either - same issue


2. I wondered if the scene scale was something to do with this, so I made an object the same scale as the building in the frame in Fusion360 and imported into keyshot via STEP. This object renders fine on both CPU and GPU. So this would imply that the supplied geometry is at fault here on GPU - why can this be? I'm downloading Autodesk Meshmixer to attempt to clean the model up


will report further findings here


thanks


D

Hello David,

Thank you for contacting Luxion.

Still nothing.
Don't suppose the file is small enough for you to attache to this message?

Referencing your Ticket ID#:21224

 

Med Venlig Hilsen / Best Regards,

Erik Williams
Customer Support Specialist
Hello David,

Thank you for contacting Luxion .
Okay I have the file and can see the error. 
​I have our team looking into this now and will reach out to you as soon as possible with any new information.

Referencing your Ticket ID#:21224

 

Med Venlig Hilsen / Best Regards,

Erik Williams
Customer Support Specialist
Hello David,

Thank you for contacting Luxion .
Our team is still looking into this issue, and for better or worse it seems to be specific only to GPU mode.
I will let you know when I have an update on the case.
This ticket may close automatically during this time, but if you have not heard from me, that does not mean the case itself is solved.

​The moment there is any new information, I will let you know.
Thank you for your patience during this time.

Referencing your Ticket ID#:21224

 

Med Venlig Hilsen / Best Regards,

Erik Williams
Customer Support Specialist
Hello David,

Thank you for your patience while our team looked into this.
The issue seems to be that all vertices are positioned ~10.000.000 units away from the origin and then transformed back. This causes floating point precision errors. 
Fixing this offset in the original cad application should solve the issue.

Let me know if that does the trick.


Referencing your Ticket ID#:21224

 

Med Venlig Hilsen / Best Regards,

Erik Williams
Customer Support Specialist
Thank you for the update David. 
​If you run into any further issues, please let us know.

Referencing your Ticket ID#:21224

 

Med Venlig Hilsen / Best Regards,

Erik Williams
Customer Support Specialist
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