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Paul Brunson
11-24-2006, 10:17 AM
I'm trying to create what I thought would be a simple texture. But so far it has me stumped.

What I'm trying to create is a earth with topo lines all around it. I need a texture that creates rings (grid, marble, ripple, underwater, corrugate) but I would like the rings to eminate from the center of a sphere.

For example if the rings were 10 m apart and my earth model was realistic scale with correct high for my APS displaced object I would essentially get topolines every 10 meters.

The only other example I can think of is I'm looking for a texture kind of like the rings of an onion. The rings are spheres eminating out from the center.

To my surprise I can't seem to get any of the above mentioned textures to do this. It seems like it should be simple...anyone know how to achieve this.

mattc
11-24-2006, 06:45 PM
I think the IFW Node package might have what you want....

http://www.shaders.org/

M.

Simon
11-25-2006, 05:36 AM
You could just do a stepped gradient based on the distance to the centre.

Simon
11-25-2006, 05:37 AM
Do you have LW9? The node gradients have pre/post repeat and you could do something like this ...

starbase1
11-27-2006, 08:14 AM
I'm trying to create what I thought would be a simple texture. But so far it has me stumped.

What I'm trying to create is a earth with topo lines all around it. I need a texture that creates rings (grid, marble, ripple, underwater, corrugate) but I would like the rings to eminate from the center of a sphere.

For example if the rings were 10 m apart and my earth model was realistic scale with correct high for my APS displaced object I would essentially get topolines every 10 meters.

The only other example I can think of is I'm looking for a texture kind of like the rings of an onion. The rings are spheres eminating out from the center.

To my surprise I can't seem to get any of the above mentioned textures to do this. It seems like it should be simple...anyone know how to achieve this.

I'm not entirely sure I understand what you are trying to do here, (and I think that others don't either!)

But I am guessing that you want lines connecting points of equal altitude, like contour lines but for the whole planet?

In this case I think you need an image map - there are plenty on the web, but for this you are likely to need a VERY high resolution one, so I suggest you look for the Blue Marble second generation height maps from NASA.

10m is way too fine, but here is something that should give you the basics.

There are two obvious ways to do this, one making a new image map, and the second of deriving one inside lightwave - the second is probably more flexible.

Take your height map and apply it to your sphere, in the colour channel.

Now apply a gradient over that, with 'previous layer' on the input. You now need to map the smooth black to white colour onto bands. To do this, first set the start and end points to black. Now add three points close together in the gradient, and set the colours to black-white-black, (or replace white with the colour of your choice). The closer together the points, the finer the altitude band you will pick out.

Repeat as necessary.

Getting a lot of contours this way will be very fiddly, and it may pay to try and find the format of a gradient and built one that directly, outside of Lightwave. Now with 256 grey levels you are going to be restricted to 128 contours max, but even so you will have a VERY busy map.

To operate directly on the image map, it's the same kind of idea - use 'levels' in Photoshop to transform in a similar manner.

I suspect from the way you describe it you are thinking in terms of slicing out strata in genuine geometry. This will not work, as the model you need wouyld be insanely detailled, and have unmanagable polygon counts. Consider that a grid 1000 x 1000 points will generate 2 million triangles, which is already an uncomfortably large number for native LW. But by using image maps you can get many times the level of detail - and is you use a normal map for the slope, it's pretty much indistinguishable from real geometry when viewing the whole planet.