[Sidefx-houdini-list] houdini, tiffs and txmake

Rangi Sutton rangi at kanuka.com.au
Wed Dec 12 19:51:47 EST 2007

Andrew D Lyons wrote:
> Well the thing is we are using the original tiff in the GL shader to
> see the texture in the viewport, and the tx file for rendering in
> prman.
You can still flip the texture in the shader, flat ss =s ; float tt = 
(1-t) kinda thing.. Rather than flip the uv co-ordinates in the object. 
OGL will continue to display it the same way.
> The tx was generated from the tiff - so they should be the same
> - but it's inverted.
I believe this is to do with the tiff header defining the vertical order 
of the image and some (most!) software ignoring it. Houdini writes it 
and reads it. If Houdini would wrongly ignore it and didn't use it then 
it would work better with other software. However it's part of the tiff 
header and the other software should be fixed rather than Houdini broke.

Where are you're tiffs coming from in the first place? Out of houdini? 
If so, set that env var you mentioned, and Houdini will flip it's tiffs 
and write the fact into it's header. Houdini will subsequently read the 
flag and display the image correctly. txmake will continue to ignore the 
flag, but now that won't be a problem. Make sense?

I'm making this up, btw.. not testing shite ;) Don't got prman here. 


> The uv's seem right, so I don't want to mess with
> them. I haven't really looked into it much. It's a problem someone
> else is having, but I wanted to see if it was a common one...

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