Blender bas releif node patch

[jpaluck]

Here is the wikipedia on the bas relief http://wiki.blender.org/index.php/Fi...-node-tree.jpg

[fwharris]

Here is the wikipedia on the bas relief http://wiki.blender.org/index.php/Fi...-node-tree.jpg

John,

not seeing anything

[CNC Carver]

Try this.
http://wiki.blender.org/

[jpaluck]

weird..I go to it by following links on this page http://www.blendernation.com/2009/06...de-in-blender/

[bergerud]

I have read the paper "Digital Bas-Relief from 3D Scenes" from which this process is taken. It is mathematical involving calculus. Instead of using the points of the 3d surface and changing their heights, the process uses the slopes (gradient field) of the surface. Maybe I can explain basically what I read that they do.

First, the gradient field:

Imagine a simple 3d bump like a hill. Think of a 2d contour map of the hill. It is a family of curves with each one representing where the surface has a certain height. Each contour curve has a height number attached to it. The perpendicular distance (in 2d now) between the curves on the contour map indicates the slope of the surface. Places where contours are close together means the surface is steep and places where the contours are far apart means the surface is flatter. Now imagine standing on the surface and looking at your contour map. If you wanted to climb up the hill the fastest, the direction to take would be the direction which takes you straight to the next contour line. At each point on the surface, this unique direction is called the gradient direction. It is the direction which gets you up the hill the fastest. Now at each point on the map, draw an arrow (vector) which points in this fastest direction. Make the length of the arrow equal to the rate at which the height in that direction increases (the steepest slope) and you have what is called the gradient vector field. It is this gradient vector field that he process uses.

The process keeps all of the gradient field directions the same and changes only the lengths. That is, the slopes of the surface are decreased but those steepest directions are not changed. (That field of steepest directions is really the esthetic geometry of the hill.) The slopes are now decreased using a logarithm function (sorry for any flash backs!). The logarithm is used because it reduces the larger slopes more than the smaller slopes. The result is the vector field of a new, lower profile hill. The new hill has to now be recovered from the new vector field data. This is a process called integration. After integration, we have a new hill with the same basic shape but is not as steep or high.

The process, of course, involves may other details and complications. What I have described is just the very basic idea. The paper, if you want to read it is at:

http://gfx.cs.princeton.edu/pubs/Wey...DBF/relief.pdf

[chebytrk]

Sounds similar to the way we read military maps when we were plotting a radio shot for our LOS (Line of Site) radio antennas. That was time consuming because after drawing a straight line on a map (about a 50mi distance) and then having to trace the line path and check the contours to see if the shot was going to hit hills or a mountain. If so, we had to set up a relay site and "dog leg" the radio shot. Not to mention tall trees and also making sure there was a road to drive our Radio Rigs and Generators to the spot. The stories I could tell ... just to get commo in. Of course now it's all done by computer and Satellite I'm sure.

I have read the paper "Digital Bas-Relief from 3D Scenes" from which this process is taken. It is mathematical involving calculus. Instead of using the points of the 3d surface and changing their heights, the process uses the slopes (gradient field) of the surface. Maybe I can explain basically what I read that they do.

First, the gradient field:

Imagine a simple 3d bump like a hill. Think of a 2d contour map of the hill. It is a family of curves with each one representing where the surface has a certain height. Each contour curve has a height number attached to it. The perpendicular distance (in 2d now) between the curves on the contour map indicates the slope of the surface. Places where contours are close together means the surface is steep and places where the contours are far apart means the surface is flatter. Now imagine standing on the surface and looking at your contour map. If you wanted to climb up the hill the fastest, the direction to take would be the direction which takes you straight to the next contour line. At each point on the surface, this unique direction is called the gradient direction. It is the direction which gets you up the hill the fastest. Now at each point on the map, draw an arrow (vector) which points in this fastest direction. Make the length of the arrow equal to the rate at which the height in that direction increases (the steepest slope) and you have what is called the gradient vector field. It is this gradient vector field that he process uses.

The process keeps all of the gradient field directions the same and changes only the lengths. That is, the slopes of the surface are decreased but those steepest directions are not changed. (That field of steepest directions is really the esthetic geometry of the hill.) The slopes are now decreased using a logarithm function (sorry for any flash backs!). The logarithm is used because it reduces the larger slopes more than the smaller slopes. The result is the vector field of a new, lower profile hill. The new hill has to now be recovered from the new vector field data. This is a process called integration. After integration, we have a new hill with the same basic shape but is not as steep or high.

The process, of course, involves may other details and complications. What I have described is just the very basic idea. The paper, if you want to read it is at:

http://gfx.cs.princeton.edu/pubs/Wey...DBF/relief.pdf

[jpaluck]

Here are some more patterns while playing around with the settings and get used to blender and the plug in. These are all free models off the net and not mine so please dont re-sell. The images have some stepping so will need to be cleaned

[jpaluck]

Lawrence I know you did this one before..I stumbled on the same and couldnt resist putting it thru bas relief plug and sculpting a bit in zbrush...fun to sculpt this or touch up

[jpaluck]

too addicted to this..I am now starting to figure out the best poses to eliminate edges as much as you can

[easybuilt]

Your doing a great job on these John. Thanks for sharing!!