Image Map Shader - tutorial?

[trailgirl]

Hi, does anyone know if there is a tutorial (or a forum post) somewhere that explains how to use the image map shader?

[rcallicotte]

I just did a search for image map shader in the Discussion thread - http://forums.planetside.co.uk/index.php?action=search2  Some sorting through, but you'll find something useful and probably some things you didn't expect.

There are a number of people wanting better documentation.  It's coming.

Is there something specific we can help answer?

[trailgirl]

thanks, Calico, I couldn't find very basic stuff in the search. I don't actually know what I'm doing  I have an image from http://hirise.lpl.arizona.edu/PSP_010580_1630 It's a grayscale jpeg. I loaded it into a new tgd file with Displacement Shader-Image Shader. I can see the terrain in the little preview window to the left of the render preview. But it doesn't actually appear in the render. I tried turning on displacement and also tried changing the scale. All other settings are default (camera projection, etc.) I also tried bringing it into tgd through Heightfield Load File, but that changes the terrain drastically and it's no longer recognizable.
[attachthumb=#]

[rcallicotte]

Do you want this as a Heightfiled or an Image for textures?  Makes a difference.  If for a heightfield, you might need to try some other Heightfiled nodes to adjust the height and the size of the displacements, etc.

[trailgirl]

This would be for making a heightfield, I'll go back to the Heightfield Load File, and play around with the settings.

[gregsandor]

Change Camera Projection to Y axis and set the dimensions of the image to the measurement in meters.

[rcallicotte]

I don't think there's a Camera Projection in the Heightfield.  I'm using a JPG for a Heightfield right now, so it works okay.

[gregsandor]

Here's an example file with a .jpg elevation model, an image map overlay texture, and another image masking a population of trees.

Changing the displacement in Example_Bump_5100m_513x will make the hills into mountains or plains; try a value of 1000 or 10 to see the difference.

Changing the Object Spacing in Pop US_Flora_TreeA.obj will make very dense or sparse forests.  You can also try running Example_Bocage_5100m_513x through a Distribution Shader or Surface Layer shader to restrict the forests by slope and altitude in addition to the image mask.

Contents Copyright 2009 Greg Sandor.  All Rights Reserved.  Do not redistribute in any form.

[gregsandor]

Result

[rcallicotte]

@gregsandor, I understand.  What I said is that I think that the Heightfield operator doesn't use a Camera Projection and I also think that Heightfields are a more effective way to create a terrain, though not the only method.

[gregsandor]

She was talking about the image map shader and in her screenshot you can see it is set to Camera Projection.

[rcallicotte]

I understand, but I still believe TG2 works better with Heightfields.  In fact, Heightfields are a good start for anyone interested in messing with TG2 and in particular are useful for more realistic terrains.  Maybe the only more realistic terrains might be the use of Georeferenced...something that Ryan Archer was bringing up in the forums lately - http://forums.planetside.co.uk/index.php?topic=6025.0

[rcallicotte]

This might be helpful in this vein of using images - http://forums.planetside.co.uk/index.php?topic=6146.msg64827#msg64827