Best Texture size to use for renders... ?

[Macho3001]

Hi all

I have recently purchased Evermotion's Textures4ever bundle and it comes with (on average) 2000 x 2000 px textures each gobbling around 4-5 MB. As is evident using this size of textures for renders grinds SU to a crawl while making models' sizes humongous. Could folks having working experience with Production renders suggest as to what size should these textures be down sampled and to what bit depth, so as to keep SU running smooth and keep model file size low. Does the texture size also impact rendering time ? And is there a way memory could be managed optimally in V-ray ( i.e. Does V-Ray have a bitmap pager like utility.... am I missing something here)?

Everyone could benefit from a general discussion on this topic,

Best w,

Macho

[dcauldwell_cg]

Re: Best Texture size to use for renders... ?

Macho
I have been pondering on exactly the same issue. I have some arroway wood textures. Typically these are 6000x6000 pix and represent an area 4mx4m.
SU doesn't handle textures larger than 1000x1000 and advise is that it doesn't dowscale them very well (or even crashes with large textures).
I have tried re-sizing the 6000 textures in PS but you loose so much of the fine detail, so I tried just clipping them, but a clipped image which is 1000 px wide then represents just 667mm, which can lead to tiling in the model.
This is as far as I've got so far, and I am thinking I need to clip down to 1000px and then work on the texture to make it tile properly.
The other course is the new SU facility to deal with larger textures, but my graphics card won't cope with this and it crashes.

Regards

David

[dalomar_cg]

Re: Best Texture size to use for renders... ?

There is no "right size" for textures. Some say that larger is better, and of course, since you can get more detail, that's a good thing. But there are side effects, mainly load time and memory...both significant issues. So the real answer is really "it depends". If you've got an object in the foreground, then maybe a 6000px image would be needed. But if you've got an object in the background and are using DOF, then maybe you could get away with 60px image.

As to technically, after loading, there's no slowdown from using larger textures. The process for finding a given pixel from the intersection with an object is the same operation no matter how large or small the image is.

As for downsizing images, I would downsize them by halves in about 3 or 4 steps. A 6000x6000 image would be downsized to 3000x3000, 1500x1500, and 750x750. That should give you enough options for images of different sizes.

[Macho3001]

Re: Best Texture size to use for renders... ?

Thanks for your inputs, David, Damien. I read elsewhere that 512 x 512 size is optimal for both near & medium-far materials. Does the original texture image still 'link' to the SU file even if the corresponding vismat's bitmap is changed to a low res version? and how does using 'resolution heavy' textures impact render time?

I was looking at more such input from folks who use these heavy textures on day in day out basis & if there are any nifty tips/ practices anyone would care to share while using such heavy evermotion/ arroway/ turbosquid textures.

It'd be great if Thom, Nomer, Damien, FreeAgent, Solo or other masters/ experienced users could throw some more light on this from their personal experience.

Thanks in advance,

Macho

[thomthom]

Re: Best Texture size to use for renders... ?

It's all relative.
There's no fixed rule, you know you use the correct size when it looks good.

I prefer obtaining large textures. The larger the better. But I sample them down to a point before you'll notice it in your render. Which is why it's good to have the original texture in a large size in case you should require a close up detail.

The reason I try to keep the size down is to ensure the model is manageable.
It's here that I find the original V-Ray to have an upper hand as you could use a low res texture for the SU viewport and then apply a non-linked material with a higher res.

You bring up an interesting question though, "Does the original texture image still 'link' to the SU file even if the corresponding vismat's bitmap is changed to a low res version?"
Maybe you can load a low res texture in SU, then SU will have the low res stored in the model, while V-Ray load the texture you originally specified which you now can replace with a higher res. ... That's worth investigating. I'd try it out now if it weren't so late. Later.

[Macho3001]

Re: Best Texture size to use for renders... ?

Thom

An intriguing post. You mentioned original V-Ray (Standalone/ Max) has this feature.. could you elaborate ? Is it possible for V-Ray to apply high-res texture to an element (say, a continuous wall starting from extreme close up & receding far back into the scene) for the near polygons & replace them with the low res one as it progresses beyond a certain 'threshold' as we have in DOF. Could you care to share if you have knowledge about proxy textures that load only at rendertime; (similar to proxy objects) ?

Macho

[thomthom]

Re: Best Texture size to use for renders... ?

Sorry, "original V-Ray" referred to the first V-Ray for SketchUp, when materials weren't auto linked.

I've not heard of proxy textures. The only thing would be in the first VfSU as mentioned before which allowed you to have non-linked V-Ray materials.

I'm not too concerned about letting V-Ray deal with large textures. It's more of a concern to what SU can handle before the model becomes too heavy. SU does some of the work in some respect here as it will sample down textures to a max of 1024x1024 (2048x2048 for SU7 if you enable large textures), but even that can some times be an overkill.

[Jackson_cg]

Re: Best Texture size to use for renders... ?

As David said SU won't display textures larger than 1024 x 1024px due to an OpenGL limitation (not sure how they worked round that for SU7, but as the new limit is exactly twice that size I guess they found a cheat way around it). Nevertheless, VfSU reads the original bitmap so you can use bitmaps larger than 1024 px (or 2048 for that matter) and they'll render not at SU's native resolution, but at the original, see below. I made no changes to VfSU's material, just used a 4000 x 4000 px as the SU material bitmap for the diagonal line, created a solid black geometry circle around it for reference and then exported one image from SU and another rendered from VfSU.

[thomthom]

Re: Best Texture size to use for renders... ?

As David said SU won't display textures larger than 1024 x 1024px due to an OpenGL limitation (not sure how they worked round that for SU7,

With a registry tweak you can enable this in SU6. http://www.sketchucation.com/forums/...hp?f=15&t=9499

[Jackson_cg]

Re: Best Texture size to use for renders... ?

2006?! Don't know how I missed that.

[dcauldwell_cg]

Re: Best Texture size to use for renders... ?

Jackson

Thanks for the info and the test results.
I have been trying to use a 6000x6000px png image for the floor texture. I don't think SU is too happy with it and kept crashing. After reading your post I tried again, after shutting everything else down, and it has rendered ok - apart from the bump which, I think, looks offset.
I'll do some more tests, but I can tell that I'm pushing the limits of my computer (2Mb ram).

Regards

David

[Macho3001]

Re: Best Texture size to use for renders... ?

could you post your results please?

[dcauldwell_cg]

Re: Best Texture size to use for renders... ?

Here is the image I'm refering to. This is still WIP.
You can see that I want a floor texture that doesn't tile. However, at the moment, when I link to the bump file it still crashes. I think I am running out of memory, so I think my best bet is to half the texture size (currently the texture is 44Mb (!), or change it to a jpg (it is currently a png). I'll try both and see how it comes out.
I am probably getting a bit picky and obsessive about this, but I want it looking right.
At the moment you can see the faint offset bump. I have the bump turned right down so it isn't very noticeable (so why am I doing it!)
While I'm at it - there is a glow coming from behind the storage boxes on the bottom shelf, on the left - wierd.

David

[thomthom]

Re: Best Texture size to use for renders... ?

or change it to a jpg (it is currently a png).

Not sure if saving in another format will help memory problems, because the smaller file size will only be for the file saved on disk; in order to use the texture it has to be decompressed.

[Jackson_cg]

Re: Best Texture size to use for renders... ?

I'll do some more tests, but I can tell that I'm pushing the limits of my computer (2Mb ram).

I hope you meant 2Gb!

I only run 1.5Gb RAM, but almost never find that limits modelling or rendering and have never seen SU crash because of large textures (though I rarely go over 3000 x 3000 px). I always use jpgs for solid materials and pngs for those with alpha tranparency, so maybe converting to jpg might work, maybe SU combined with 2Gb RAM just can't cope with 44mb pngs (that is HUGE!).

Jackson