Arnold Tyflow GPU anomaly

[Dantetron]

Has anyone else encountered this weird anomaly while using Arnold/GPU render/motion blur? In this case, it's a simple birth object process. The same occurs when I use the birth operator using 3D sphere shapes within Tyflow.

The black overlaps do not show up rendering with CPU. Nor do they show up with motion blur turned off.  Those are the only commonalities in this situation.

Thanks!

[cerakecera]

I wouldnt expect any solutions or fixes when it comes to arnold GPU. Trust me i wasted good time looking for answers and support...

[Dantetron]

Thanks, Cera. 

I’m starting to see that.

And I’m glad to see I’m not the only unpaid “beta tester” out there for Arnold GPU. 🙂

To their credit, I did receive a response on another matter where I discovered that there is a considerable rendering inconsistency between CPU and GPU. And they openly said they’re addressing the “bug” and finding its root cause. 

But you’re right, I got crickets on this one.  I’m assuming because 1) it involves a 3rd party app and 2) I figured out a work around. 

I spent some time with the Tyflow folks and it sure appears to be an Arnold issue. 

[Stephen.Blair]

If you have an Arnold subscription, you should be logging a support case. The Autodesk forums are community forums, not official Autodesk support.

How do I reproduce this? Can you post a simple ASS file that shows the problem?

[Dantetron]

Hi, Stephen!

As always, I appreciate the time and attention. I've attached an .ass file of the cuprate.

Again, the issue only shows up when-

1) the objects are particles

2) Arnold renderer

3) GPU render

4) Motion blur is on in physical camera

ALSO!!! A development.   I've been able to replicate this problem with any object type in tyflow... until I installed the new 2023.3 update!   However, this project I'm sending you was created in 2023.2 and still shows the anomaly.

THat has made my trial and error more complicated so let me know if you're getting the same result with the .ass I'm sending you.

Thanks!

[Stephen.Blair]

---

@Dantetron wrote:

Hi, Stephen!

As always, I appreciate the time and attention. I've attached an .ass file of the cuprate.

Again, the issue only shows up when-

1) the objects are particles

2) Arnold renderer

3) GPU render

4) Motion blur is on in physical camera

ALSO!!! A development.   I've been able to replicate this problem with any object type in tyflow... until I installed the new 2023.3 update!   However, this project I'm sending you was created in 2023.2 and still shows the anomaly.

THat has made my trial and error more complicated so let me know if you're getting the same result with the .ass I'm sending you.

Thanks!

---

Thanks, but unfortunately I don't see any problems when I kick that file. I did have to ignore the missing textures, but I did see motion blur on the falling bullets. And everything else looked ok.

I wonder if I'd really need a 3ds Max scene file. Unless you can repro by kicking the ass file?

I was doing something like this:

C:\ProgramData\Autodesk\ApplicationPlugins\MAXtoA_2022\kick -v 5 -dp -it -is -set options.abort_on_error off "C:\Users\stephen\Downloads\tyflow bullet.ass" -device gpu

Later I created a new scene and loaded your ass file as a procedural, and assigned a default standard surface, so I could see things better. That still rendered ok.

[Dantetron]

Stephen-

All makes sense.  Let me beat on it more now that I have 2023.3 installed. If I can't reproduce it then, yay, we fixed it! 🙂

[Dantetron]

Hi, Stephen!

Ok- I was able to put more time into the issue with ver 2023.3 and the anomaly is still occurring.  I've added a zip file containing a MAX file and necessary texture maps. Also in that zip file is a single render called "test.jpg" showing what's occurring on my side (frame 40 is rendered in this case).   I've kept everything as simple as possible without changing any defaults. Here's some detailed information to note...

-All versions and drivers are current

-A reminder that this anomaly only occurs using the GPU for rendering while motion blur is ON.

-The anomoly is occurring to particle objects

-I'm using an EVGA 3060ti GFX card for my GPU rendering.

Let me know if I can provide anything else to assist!

Thanks!

[Stephen.Blair]

---

@Dantetron wrote:

Hi, Stephen!

Ok- I was able to put more time into the issue with ver 2023.3 and the anomaly is still occurring.  I've added a zip file containing a MAX file and necessary texture maps. Also in that zip file is a single render called "test.jpg" showing what's occurring on my side (frame 40 is rendered in this case).   I've kept everything as simple as possible without changing any defaults. Here's some detailed information to note...

-All versions and drivers are current

-A reminder that this anomaly only occurs using the GPU for rendering while motion blur is ON.

-The anomoly is occurring to particle objects

-I'm using an EVGA 3060ti GFX card for my GPU rendering.

Let me know if I can provide anything else to assist!

Thanks!

---

So far, I'm not getting those artifacts. I have a much older, lower-end card, but it's rendering ok in the Arnold Render View