Hi Xiaofeng, The Chimera Color Zone tool has lots of limitations as you've noticed. The jagged edges on the colored region when using color zone happen because the surface is made up of triangles and Chimera can only color each triangle vertex and then linearly interpolates colors across the triangle based on the 3 vertex values. That can look bad. Your solution of using the "subdivide surface" option in the volume dialog surface surface and mesh options panel will help reduce the jaggedness. There is one tricky solution that can produce a smoother edge. It uses a command I just added a month ago called "measure contactarea". The virtue of this approach is that it creates a new surface chopping the triangles at the edge of your zone to make a perfect smooth boundary. But it wasn't intended as a substitute for the color zone dialog. Instead it measures the area on one surface within a given distance of another surface and displays that contact area. The first problem using this is that it doesn't use markers and a surface like color zone -- instead it uses two surfaces. So the first trick is to turn your markers into a surface. If the markers are model #1 use molmap #1 3 to make a 3 Angstrom resolution surfaces for those markers. Now to color a zone around those markers on volume data #0 use measure contactarea #0 #1 12 color tan This will make a new surface matching volume surface #0 within a range of 12 Angstroms from surface #1 (the marker surface created with molmap). It has beautiful smooth edges. See the attached picture. You'll need a Chimera daily build to use "measure contactarea". I suggest tonight's daily build, because I made some changes to "measure contactarea" to make the surface look very smooth. Earlier daily builds had a less smooth edge, and less smooth colored region. If you add "slab 2" as an option it will make the colored patch have thickness 2A (not shown). 1) You can't use different color zone radii on the same surface at the same time. This is item 37 in the Chimera feature request list. http://plato.cgl.ucsf.edu/trac/chimera/wiki/requests You can use the above trick multiple times to create color patches using different radii. 2) Not sure I understand this question. I think you are asking if you can color inside rectangles and ellipses. There's no way to do that now. I'm not sure how you would describe the rectangle or ellipse with a marker since a marker is a sphere and those shapes have non-equivalent axes. You can create such shapes with the Chimera "shape" command but you can't for instance color everything within such a shape. The closest you can do is color near a traced path made with markers and links. This basically lets you color in a cylindrical zone. To enable this you use the bondzone command http://www.cgl.ucsf.edu/chimera/docs/UsersGuide/midas/bondzone.html 3) Not sure exactly what case you are interested in. If you clip a surface you can place markers exactly of the "cap" surface that covers the hole left by clipping. You would use the Volume Tracer mouse mode with "Place markers on surfaces" enabled. If you wanted to place markers on single data planes of a volume you would enable "Place markers on data planes". Tom
Dear Chimera users,
I always have problems when I color a sub-region of density map by markers. Rather than a zigzag, boundary, I try to create a smooth curve boundary of sub-region from a whole density 3D volume. In this case, if I just put one marker and select a big coloring radius, the boundary in cross-view will show a circle curve at the boundary, however if I use a very small coloring radius and put more and closer markers on the boundary, the boundary shows a sawtooth in cross-view, even I choose 4 times for subdividing surface. Or is there any other way to do this instead of markers? And I have several other questions: (1) Is that possible to have different coloring radius in one Chimera session? (2) except for ball shape, can we have more options on the coloring object with markers? For example rectangular, ellipse and so on. (3) Is that possible to put markers directly on the clip planes?
Thanks in advance, Xiaofeng
