Using huge textures in Vray with ease.

[Metzger]

This has been a huge battle for myself. I originally was using an exrmaketiled command in linux to create tiled mipmap exrs. Not sure where it originates from but no matter what options I used the results were never what I wanted. Even with mipmap turned on I would get all sorts of strange exr options that I do not need along with a wavlet compression that was automatically being added. Well a coworker of mine urged me to try out Pixars txmake for creating tiled mipmap's. txmake works perfectly. All I can say is wow my life is changed. 5 minute texture loads when using the VFB are now instant.

txmake -format openexr infile outfile

Get a hold of txmake and give it a shot. If anyone has any luck using anything else for creating tiled mipmap exr's please share in here.

Thanks!

-Scott

[snivlem]

Thanks for sharing this tip - where do I download txmake though? All I find on Google is the help docs for it.

EDIT: Guess it comes bundled with renderman?

[Metzger]

Yeah, it comes with Renderman. Perhaps someone else could share another app that does a great job at properly creating tiled mipmap exrs.

[aweidenhammer]

Thanks for the info. We don't have renderman, so it continues to be a problem for us here. I noticed JupiterJazz is working on their own makeTiledEXR converter, but I don't see anything released. I emailed Paolo, so I'll let you know what happens. At least you have a solution

BTW, ChaosGroup, this might be a nice utility to include with vray *hint hint*

[instinct]

OpenimageIO also comes with a utility to do that. I dunno if it does the trick tho. Plus there are no binary distributions yet, so you'll have to compile it yourself.

Regards,
Thorsten

[Reaversword]

Ey guys, this you're talking about is really interesting.
If I have understand it well, you're talking about a function for texture pyramidal compression like .map files of Mental Ray, aren't you?.

Any real solution yet?. OpenImageIO works?. Some renderman demo version with the utility txmake without limitations?.

The other day I leave doing a render, go to dinner and when I back the proyect was eating the computer... I should hit them with a stick and put them the strap... here is, sleeping outdoor.

Would be great to have a Chaos utility for do this. I'm sure then my 32 and 64 bits computers would make the love often through vray.

[vlado]

There is also exrmaketiled from the OpenEXR library itself, but it tends to blur the mipmaps a bit too much. Anyways, will see if we can make a tool for that.

Best regards,
Vlado

[Reaversword]

I'm taking a look more deeply at exrmaketiled, but after read this: (or at least, part of them)

www.openexr.com/ReadingAndWritingImageFiles.pdf

I have some questions about Vray and pyramidal exrs:

How Vray uses it?. Depending of the distance to the camera, object size, final image resolution... I guess. right?.

What's the condition for Vray gets 2k version, 1k, 512, 256... etc?. First read all levels in the texture and then choose the best?. If we have a ext texture for example, in a long wall which is near the camera and far away too?. In this case, Vray chooses load the full size?.

As for example, Softimage uses .pic, Maya .iff, Mental Ray .map for optimized scenes, the correct way would be that Vray haves its own format, or simply optimize it for one of the much formats that exist yet?.

Anyone knows a visor for see MipMapped (or RipMapped) exr tiled textures? (I mean all the pyramid)


Well, the only I don't understand is the "-f" option, I understand that with "-f r -f g -f b -f a" you're deactivating low-pass sampling for rgba channels (maybe the blurred images?), but if you have in the exr some layers... should be -f specularlayer.r .... and g,b,a?. Appears the pdf doesn't says anything about what's low-pass sampling and how improve quality...

And I suppose that -t option (tile size) its only for non-mipmapped images, I understand mipmapped images size is defined for the 0 level.

[Metzger]

Ptex is going to be the future for textures. If we are using Ptex we won't have to deal with all of this. Currently I load all textures into Nuke, convert from sRGB to linear 16bit exr or raw 32bit for displacement. Then I write those out as exrs. I then run a python script that uses txmake to convert the whole directory of exrs to tilable exr's that are also mip mapped.

I never have load issues with textures at all with Vray. Superfast.

Vlado: I was using exrmaketiled, but had horrible results using that. It seemed to always put some strange wavelet compression on the image causing nothing but horrible images. Txmake is supersoild and works great.

[gardeler]

Very interesting! Thank you for sharing.