Hey guys, how are you refreshing textures in XPU? Since .rat files on xpu I've got issue when updating textrues (in that scenario I'm using cops and render them to disk) but houdini doesnt udpate .rat files whenever original textures is updated. I cant even delete this rat texture without closing houdini because windows says its being used

render menu -> update textures ?

I've often wondered about this myself, but I don't think it's possible to refresh textures. I imagine the intended workflow is to increase the version in the file name any time you update a texture.

A few things you can try are mentioned in this thread. Seems you're not the first to run into texture refresh issues.
https://www.sidefx.com/forum/topic/81603/ [www.sidefx.com]

I dug into this some more to try to get reproducible steps. Here's what does and doesn't work for me on Houdini 20.0.610 on Windows 10:

Karma CPU

- Can't overwrite texture while CPU running
- Can't overwrite texture while CPU paused
- Can't overwrite texture after switching to GL
- Can overwrite texture after switching to XPU
- Once CPU releases the texture then it reads the updated texture without any extra steps

Karma XPU

- Can overwrite texture at any time
- Pause or restart does not update texture
- Switch to GL, Reset Karma XPU, switch to XPU does not update texture
- Render > Update Textures while XPU running does not update texture
- Render > Update Textures, restart render, texture now all black
- Repeat above step again, texture now updated
- Render > Update Textures, switch to GL, Reset XPU, switch to XPU, texture now all black
- Render > Update Textures again, restart render, texture now updated

I think there are some other combos that work with XPU, but you get the idea.

Long story short, neither CPU or XPU gets it right. CPU locks the texture, XPU does it right. CPU updates the texture without any extra steps, XPU does not. I think the way it should be in both CPU and XPU is the texture never gets locked and it updates automatically.

BrianHanke
Karma XPU

- Can overwrite texture at any time
- Pause or restart does not update texture
- Switch to GL, Reset Karma XPU, switch to XPU does not update texture
- Render > Update Textures while XPU running does not update texture
- Render > Update Textures, restart render, texture now all black
- Repeat above step again, texture now updated
- Render > Update Textures, switch to GL, Reset XPU, switch to XPU, texture now all black
- Render > Update Textures again, restart render, texture now updated

I think there are some other combos that work with XPU, but you get the idea.

Long story short, neither CPU or XPU gets it right. CPU locks the texture, XPU does it right. CPU updates the texture without any extra steps, XPU does not. I think the way it should be in both CPU and XPU is the texture never gets locked and it updates automatically.

did you get the automatically generated rat files to regenerate? XPU doesn't use the textures directly if they don't have mip maps.

I wonder if the hscript command texcache -c will delete them, or if the external command line htexcache -c is needed.

Yes, the XPU steps create an updated .rat file (the original texture is .jpg in my test). Here's a clip showing the texture corruption that happens with texcache -c (which I assume is what Render > Update Textures is doing).

BrianHanke
Yes, the XPU steps create an updated .rat file (the original texture is .jpg in my test). Here's a clip showing the texture corruption that happens with texcache -c (which I assume is what Render > Update Textures is doing).

yikes

It's kinda hard to use the Karma for look dev if you can't update a material texture to try things out.

Any update on this issues? I use a material baker to create textures and when I bake the textures new files are written to disk, but the materials in Houdini do not update. The *.rat files all seem out of date. "Render" -> "Update Textures" is not doing anything. I am using Houdini 20.5.550 and Solaris Karma CPU/XPU (neither works).

No updates that I know of...

any news about this?

Ouch....
Just run into this problem and indeed is kind of a serious issue for look dev.
I have been trying to set up a smooth workflow to completely replace the substance package with copernicus and even with the limitation on UDIMs I was sure I could find something but if basically I need to restart Houdini everytime I want to reload a texture then that is a no go.

I just revisited this in Houdini 21 and the situation with Karma is slightly worse. XPU now locks textures too and no amount of updating textures or restarting renders does anything.

It's not a Solaris thing. RenderMan 27 works great: no file lock, change your texture, click restart and the render instantly updates to the latest version.

BrianHanke
I just revisited this in Houdini 21 and the situation with Karma is slightly worse. XPU now locks textures too and no amount of updating textures or restarting renders does anything.

It's not a Solaris thing. RenderMan 27 works great: no file lock, change your texture, click restart and the render instantly updates to the latest version.

We did find a file lock bug relating to non-RAT textures on CPU on Windows, but otherwise unable to reproduce the problem in any other combinations.
Can you please file a bug, including your platform, texture format, and a reproducible case if you have one. Thanks.

dlee

BrianHanke
I just revisited this in Houdini 21 and the situation with Karma is slightly worse. XPU now locks textures too and no amount of updating textures or restarting renders does anything.

It's not a Solaris thing. RenderMan 27 works great: no file lock, change your texture, click restart and the render instantly updates to the latest version.

We did find a file lock bug relating to non-RAT textures on CPU on Windows, but otherwise unable to reproduce the problem in any other combinations.
Can you please file a bug, including your platform, texture format, and a reproducible case if you have one. Thanks.

Sorry I also went ahead and did a bug report.... I had a test file ready from my previous testing of UDIMs in Cops.
Here is a video showing the bug FYI.
texture bug... [www.dropbox.com]

bug #152086

I tried your scene and initially it worked and the textures updated without any problems. Then this happened! It's odd how unpredictable this is. I'd like to submit a report but I honestly don't know how to do so constructively since the behavior feels random on some level.

ok.. this is crazy in my case textures do not update at all. just the first time you create them is like XPU refuses to create new rat files. But if you close houdini and open it again everything is fine.

I got it to work!!!
So I updated my nvidia driver to latest game driver rather than studio and everything seems to be working fine now.
Don`t know if this will help anyone else but here it is.