Hi

Anybody know of a tutorial on how to import dem data or geotifs in houdini to create realistic maps -

Failing that, does anybody know how to do it?

Many thanks

Jake

I've never tried but perhaps this mailing list thread may help you:

http://www.sidefx.com/index.php?option=com_mailarchive&Itemid=212&view=IDX&exactsubject= [sidefx.com]%20importing%20dem%20data&perpage=20&revdate=off

Thanks Edward I'll give them a look

Hey Edward is this Mail List very active?

Sty
Hey Edward is this Mail List very active?

It's active, but it doesn't get a lot of traffic these days. I think a lot of it moved over into the forums.

i see…i subscribed and nothing until now

Sty
i see…i subscribed and nothing until now

There's been no posts. You can always see the web archive here (and note the sparsity of the traffic)

http://www.sidefx.com/index.php?option=com_mailarchive&Itemid=212 [sidefx.com]

Handling geotiffs is reasonably easy.. they are in fact just tiffs with a bit of additional metadata.

It depends on how they are made, but usually they contain a simple height map representation of the surface, with the values in meters.

If you look at them with a viewer like xnview they will most likely look 100% white, depending on where the snippet is from, the expected values are something like 100 to 4000 for the Swiss Alps for example.

So you can either:

- use a tool to convert the range (I use Nuke for that, but you can use all sorts of tools) to 0-1
- leave the range as it is and deal with it in the displacement shader

You would then convert the tiff to a .rat (using the normal iconvert workflow, like “$ iconvert alps.tiff alps.rat”), put down a grid in houdini and use the .rat you just made as a displacement map.

Either way, if you left the values like they are or converted them to 0-1, you will have to take care of the overall scale yourself (so that the height matches the grid length)

For a quick viewport preview, you can sample the map in VOPs and just push up the grid points accordingly.

One thing you have to remember: most geotiffs I encountered don't clip at the sea level, but include underwater scenery.. so if you want to have a flat water surface, you might want to clamp it at some point.

That's basically it.

edward

Sty
i see…i subscribed and nothing until now

There's been no posts. You can always see the web archive here (and note the sparsity of the traffic)

http://www.sidefx.com/index.php?option=com_mailarchive&Itemid=212 [sidefx.com]

Oh man, thanx again..i thought i was going to receive email notifications for every new post