Hi-poly to normal map? how

I have a question that spans a couple of forum (but no one visits texturing so I’ll post it here since its intend for use in the ge) How does one go from a hi-poly to a normal map and low poly. The tools:blender,gimp,and sharpconstruct. I figure I’ll start with a lowpoly model and sculpt it in sharpconstruct. But is there even a means to getting a normal map out of the hi-poly model. I could have sworn i’d seen a post similar to this where a tool from nvidia or ati (pretty sure ati) was mentioned, but I didn’t manage to find it. Any help would be appreciated.

Also I was curious if anyone has done this yet using the free apps and wouldn’t mind giving some insight on workflow. Such as using the lowpoly uv map and getting the high poly normal to fit it.

I always ask to quick. Melody from nvidia. Sorry

or in blender… take a high-poly object. Give it three blend-textures.
first->map input: nor, and only X clicked in the 3×3 thing, map to: change mix to add and the color to all red
second->map input: nor, and only Y clicked in the 3×3 thing, map to: change mix to add and the color to all green
third->map input: nor, and only Z clicked in the 3×3 thing, map to: change mix to add and the color to all blue

render with an orhto-camera…

check http://www.blender.org/cms/Normal_Maps.491.0.html the preview of your texture should look like the first pic.

it’s esier for flat objects… I made a hight poly wall of (VE:7720)*, made a normal map of it and applied it to a plane. Worked great! A good way of reducing polycount by 7716… I’ve only tried it in rendering, not GE, but it will work since the map is the same.

*modeled a stone and copied LOTS of times until I had wall

This is where I learned from:
http://mediawiki.blender.org/index.php/Manual/PartIV/Bump_and_Normal_Maps

I was think more for game character design … 3d geometry But I failed to mention that in the initial post. This does seem like a very compelling way of creating normals for 2d. I’ll certainly be adding it to my list of things to play with.

If its any help theres a Photoshop plug-in that makes normal maps…

heres a pick …https://mywebspace.wisc.edu/jgphillips/web/normalheads.JPG?uniq=-db53ch
This shows what the two separate models look like side by side in Melody after the normal map has been produced.

Used sharpconstruct first, then went to blender and built a low poly, then imported to melody for the awesome stuff.

Had to play with melody for an hour or so before I had something that wasn’t only partially complete.

100000 faces for left model, 296 faces for the right model with a normal map.

Problems that I came across.

  1. Sharpconstruct currently can’t support rediculous amounts of polys so I used subdividing in blender then went back and forth between the two. The crease in the center of the chin happened where the heavily subdivide area meets the lesser. I haven’t tried using the subdivision w/ masking in sharpC yet so it maybe better.

  2. Melody seemed to have issues if the two models are very similar sizes. So when I first built the low poly I was simply creating a second head right on top of the hipoly head. This made it obvious where a plane on the low poly was intersecting the highpoly area. So I was forced to scale the low poly head to be bigger than the hipoly, then the lowpoly head could complete encapsulate the hipoly head without intersections. After that I was able to play with the option and get melody to create a full normal map. Otherwise it was struggling, but this might just be me not understanding the options well enough. (might post a pic later showing what I mean exactly)

  3. Melody can import the uv layout along with the an .obj file so the normalmap can be produced to fit your blend uv layout. I’m still trynig to find the “give me my normal map button” lol, got tired last night.