TX texture vs JPG/TIF (why is TX slower to render ?)

[eligiusz]

Hi,
I've done some tests comparing performance of TX textures in vray HDRI loader versus JPG/TIF in 3dsmax bitmap loader.

Render times:
3m 15s - JPG/TIFF
3m 48s - TX

Ram usage:
12850 mb - JPG/TIF
4550-5230 mb - TX
but why is TX slower to render ? I was hoping that it would work like in the link here: https://support.solidangle.com/displ...A+Wooden+Floor

For the test I have used 5 renderpeople models with 8K textures and HDRI lighting. For TX version I increased the texture cache to 12000mb.
The textures were converted with '-v -oiio' maketx parameters.

[Dave_Wortley]

TX isn't about making your image render faster, it's about being able to have more texture information than you could possible hold in your Ram as it dynamically loads in and out when required.

Unfortunately the process of loading the texture in and out will be slower than just having it in memory. but you can have 500GB of textures as tx and still rendering, try that with normal exr are 32gb of Ram.

[eligiusz]

so why it is in arnold about making it render faster ?

[Dave_Wortley]

It might be to do with 3dsmax loading the JPEG textures into memory before the render (through the material editor for instance) with VRay and Arnold loading them at render time.

I'm sure Vlado will be able clarify.

[vlado]

so why it is in arnold about making it render faster ?

<shrug> For better or worse, V-Ray is not Arnold. On the bright side, look at it like this: JPEG/TIFF is slower in Arnold. As far as I know, Arnold is very specifically optimized for TX files, whereas TX files have never been about speed for V-Ray; their main advantage is on-demand loading and controlled RAM usage.

Best regards,
Vlado

[Morbid Angel]

In maya there is no texture cache between renders in arnold (as far as I recall) However, the advantage of tx besides what already been said here is it does load faster at distance, since it uses smaller tiles. In your render all characters are close to camera so its loading a full res texture. If you take out from equation the fact that the .jpg and other textures are in ram after first render so you don't read them from disk, .tx always reads from disk (correct me if im wrong here). So I think this is where the slow down might happen.

[eligiusz]

Maybe its not the tx file itself but the vray hdri loader?
because when i put tif files in vray hdri loader instead of bitmap loader ir renders slower
render times are a bit strange because the first time i render its 4m2s and second time 3m31s and with 'bitmap' its 3m15s

thanks for interest and replies, im just trying to understand whats going on here and also to have best performance possible.

[vlado]

and also to have best performance possible.

If that is all you are after, stick to the 3ds Max Bitmap loader.

Best regards,
Vlado

[Morbid Angel]

If that is all you are after, stick to the 3ds Max Bitmap loader.

Best regards,
Vlado

You only really need .tx as mentioned above, if you have thousands of textures and you are running out of ram and can't render your scene.

[eligiusz]

I feel like You dont understand me. I dont have thousands of textures in my scenes, did You look at the ram usage ? You only need to add a couple of 3d people models and You are done, I'm doing arch viz and animations also so i need ram performance and render performance, every second counts in animation. So i want to set it up for controled ram usage and best performance possible (with this ram control)

So im not going to stick to the bitmap loader !!! actually I'm thinking about converting all the big textures to tx, thats why im exploring this subject.
I only have 32 gb ram on my workstation and 48GB on render slaves and with last two projects it was full ram usage so I have to figure something out.

[Morbid Angel]

On the contrary, I understand you perfectly. Trust me, I deal with the same subject matter on a daily basis. When you deal with a lot of data, performance is always sacrificed. If you are close to using all your ram as you said before, in this case its best that you use .tx as much as possible. If you look at your render time difference, its not that dramatic. If the question becomes: you can't render the scene at all, because you run out of ram, then using .tx and dynamic geometry in general will get the render done, though slower, but better have it done at slower pace then not having it done at all.

Controlled ram usage is an arbitrary statement. The dynamic memory is split / shared between dynamic geometry and dynamic textures. You can't explicitly macromanage each megabyte, though there are controls to limit how much ram is used by dynamic geometry and textures, vray does a good job of autobalancing this.

[eligiusz]

Thanks Dmitry, I have watched Your reel, You do amazing stuff.

So I'm wondering now what parameters I should use when converting 8-bit textures to .tx? Like for example the tile size ? or the MIP level ? what kind of filter ?
Do You have any thoughts about it ?

edit:
when I increased the quality settings the render times are as follows:
8m32s and 10m31s
so the gap increased

[Morbid Angel]

What are you using to make the .tx? I think we default to 64 tile size, but I can't remember exactly. Also in maya arnold has its own .tx tool which probably does some optimizing as well, perhaps its worth looking into what it does there.

If you want to post this scene for me I can see if I can make it quicker to render using my .tx tool and get you the settings.

[vlado]

The maketx tool comes from the OIIO library, I don't think Arnold adds anything specific to it.

Best regards,
Vlado

[Morbid Angel]

The maketx tool comes from the OIIO library, I don't think Arnold adds anything specific to it.

Best regards,
Vlado

Is that function now build into vray? Sorry I'm out of the loop on max side of things.