hey andy,
If the pyramidal textures are working correctly this should already be
happening, it's really the whole point of them really.
If mental ray is handling them the way most pyramidal textures should
be handled, there is header information telling the renderer how many
levels and what resolution those levels are. The sample area is
calculated and the correct level is sourced from disk, thus
effectively ignoring the higher res levels - and MR should already be
doing this adaptively.
If there is a way of explicitly setting the texture for each pyramid
sample you should be able to give the pyramid a red, green and blue
map for the different levels. Apply this map to your geometry and
pull away from it and you should be able to visually see what level of
the pyramid MR is choosing based on your sampling settings.
You'd probably end up with more problems if you break the texture up,
just more disk thrashing etc.
You really should run some tests to see if the maps you created are
being used correctly by MR, the renderer might be accessing the
highest res texture all the time even though it should be using the
different levels.
colin.
On 4/01/2008, at 8:27 AM, Andy Jones wrote:
> I guess part of what I'm getting at is that I'd like to see that
> workflow (of down-rezing) absorbed into the pyramidal map format.
> I.e., I'd like to be able to have an 8K texture on disk, but tell
> mental ray to ignore the bottom layers to make it behave like a 2K
> texture (or whatever I specify). Or, better yet, MR would do that
> adaptively, with as little performance loss as possible.
<snip>
>
> Oooh, wait -- I just got an idea. Maybe the 8K texture should just
> be tiled into separate 2K textures (or whatever size is deemed
> efficient -- probably it would be a user setting). There's a small
> amount of redundant data, but it would typically be pretty
> negligible, I think. You could implement this sort of thing
> manually, in the form of breaking your texture apart into separate
> textures, but really what you want is something that's encapsulated
> in the .map format. Otherwise, dealing with seams will always be a
> nightmare, and even if you get the UV's to line up, you won't be
> able to properly filter across them.
