Making a normal map from a displaced mesh?

[Grimoire]

I want to import a flat plain, subdivide u pto a few hundred thousand polys, import a greyscale bump map, apply ot to the plain as a displacement, and then get a normal map from the displaced plain.
I'm ok for most of it, but how to I get ZB to create the normal map from the displaced plain, and not the flat base one (which it is currently doing)
Is their anyway to freeze the object with the displacment, so it actually becomes geometry or something?

[Game Master 770]

both normal maps and displacement maps are made the same way in zbrush. u need a low poly version and a high poly version. The difference is your map, based on which low level you have selected. if your result is flat, it's cause you have your high res version selected (no difference)

[Grimoire]

I'm not generating the displacment map in ZB, I'm using an imported image in the alpha channel. I need to apply it to a high res mesh for the little details to show. I subdivide the mesh up to level seven, then drop it dow to 6 and hit the 'cage' button.
When I generate the normal map it ignores the displacment on the mesh and just treats it as a flat plain.

[Game Master 770]

I'm not sure in this case. if you can somehow embed the displacement in the highres model, you can replace your zbrush high-res model with it, then generate normal map as usual. maybe somebody else had this situation.

[Grimoire]

There must be siome way to do this, I would have thought it the perfect, fastest technique for making normal maps to go with your wall/floor textures etc.
I could do it in lightwave, but it doesn't handle 300000 poly objects very well, in fact it takes about 20 mintues just to subdivide a plain up to that level in the first place and it crashes half the time.

[skycastle]

You can do this. There have been some
good tutorials on the forum. But basicly
you import an image to the alpha menu.
Then with your tool drawn in the canvas goto
tool:displacement. Turn on the "mode" button. Set an intensity value then hit apply dispMap. Once your happy with the amount of displacement in your mesh go back
down in subD levels to level 1. Next goto
tool:geometry and turn on the cage button.
Then in the normal map tab turn on "tangent"
and create your map.

[Grimoire]

Thanks. I knew this must be a well used technique.