Optimized textures for Vray?

[Reaversword]

Is the format vrimg, besides 32bits exr brother, some kind of memory optimizer at render time?, I mean, have some equivalent for vray like .map textures haves for mental ray?

[vlado]

You can use tiled OpenEXR files with mip-map information. You can generate these using the "exrmaketiled" tool which is part of the OpenEXR library (http://www.openexr.org). Make sure that you generate the mip-maps (the -m option), as otherwise V-Ray will have to load the entire file anyways.

.vrimg files may also work (that was the intention at least), but the feature is not well tested and there may be issues.

Best regards,
Vlado

[Reaversword]

Thanks for the info, Vlado.

[Hoegaard]

Does this mean that you have to apply a filter of Mipmap to each texture? What if a different filter is used, such as Quadratic? Would it cancel the effect?

[Hoegaard]

Has anyone else encountered an extreme slowdown when using tiled exrs? I was running into a memory cap issue that ground my renders to a halt, and switched out to tiled exrs. That quickly fixed the memory issue, which is awesome.

However, a sample test scene with a few tifs took 1.5 minutes to render, while the same scene with tiled exs took 25 minutes to render.
Any ideas?

Are there particular nodes in the hypershade that are slow with exrs as textures, such as the math opps or gamma correction?



Thanks!

[Hoegaard]

DYNAMIC.
MEMORY.
LIMIT.


woops. Solved my own problem but upping the Dynamic Memory limit from the default 500Mbs to 4000Mbs. Now my renders chew through the exrs.

[vlado]

If the dynamic memory limit is too low, V-Ray will flush the texture tile cache too often, which reduces the render speed.

Best regards,
Vlado