Lookup Tables In Vex

[Jens]

I have the following problem: In a VEX shader I have a fairly complex formula and rather then evaluating it each time I'd like to use a lookup table. As far as I know VEX won't allow us to to create an array containing ~500 entries.

There are currently two solutions I came up with though I don't like either one much.

i) Store a few values and use something like a spline interpolation (much slower then a lookup, though still more effecient then evaluating the 'big' formla)

ii) Using 4x4 matrices and building something like a binary tree with 'if - instructions' (fairly fast, but takes time to implement / time to write a small tool to automate it)

I don't like either solution much and wonder if anyone has come up with a smarter solution.

Jens

[crunch]

I have the following problem: In a VEX shader I have a fairly complex formula and rather then evaluating it each time I'd like to use a lookup table. As far as I know VEX won't allow us to to create an array containing ~500 entries.

There are currently two solutions I came up with though I don't like either one much.

i) Store a few values and use something like a spline interpolation (much slower then a lookup, though still more effecient then evaluating the 'big' formla)

ii) Using 4x4 matrices and building something like a binary tree with 'if - instructions' (fairly fast, but takes time to implement / time to write a small tool to automate it)

I don't like either solution much and wonder if anyone has come up with a smarter solution.

Jens

A texture map?

[sibarrick]

A point cloud?

[Mario Marengo]

A DSO?

... if we assume that the "big formula" is complex enough that it's no longer just a matter of hallucinating a way to store its static data in VEX but also of accessing it efficiently...

Might as well do yer fancy binary/red-black/K-d/whatever storage along with all the number crunching over in C++ land, no?

If it's big/complex enough, then whatever overhead calling the dso might incur should become negligible by comparison (i.e: it should perform the fastest).

[Jens]

All solutions seem fine, thanks for the input.

I want to keep everything with VEX if possible and I like the idea using a texture to store the values most (basically I'm most familiar with that ). However I have one problem.. getting the data into the texture. Is there a simple way to create a texture from data assuming I have created the appropriate r,g,b values to represent the data and have it in a text file? Like a two-liner with hscript ?

Writing a small program for that with java wouldn't be that much of an effort.. but if I can avoid it, all the better.

[edward]

Pixel COP?