Complex UV Mapping The Easy Way

I have to admit, I didn't make this one up, but I observed it in some great models I got from Al3d. I'm glad he left in the leftovers on those models or I'd probably never thought of this.

Say you've got a model with various sundry shapes and surfaces, none of which are precisely Planar, Cylindrical, or Spherical. Yet, you want to set up some UVs on one of these surfaces. The built-in tools in Lightwave make it fairly difficult (granted, I'm not really experienced at this, so I could be missing something here). You can select some polygons, click "Assign UVs" and then you get your choice on one of the built-in projection types. But what if what you want to apply on to isn't quite facing the right way? I've tried transforming the UVs after assignment, and all I ended up with was horrible distortion.

The thing to remember is the UV coordinates are assigned to points. Once assigned, they're constant, no matter what transformations you place on the points. The trick here is we're going to apply a transformation before we assign the UVs. The trickier part is the transformation we apply will be disposable (no need to get tricky with Undo, or with some funky plugin).

Just create a new morph-map for your object. Then select the morph map. Now rotate, move, scale, whatever the model so that a simple projection is possible. Select the polygons, assign the UVs, then dispose of the morph map. That's it!

Here's an example: I've got a Viper model, from Battlestar Galactica. Here's an image of a wing:




I want to add the "NO STEP" image to where I've got green lines. The problem here is any planar projection is going to leave me with seriously distorted images. So, I make a morph-map. With the morph map selected, I'll rotate the wing so that it's not banked over:


Then rotate it so that the wing is aligned to my intended text alignment, and select the relevant polygons:


Create a new UV map with a simple Y projection (using defaults):


At this point, you can dispose of the morph map (or continue rotating for more applications). The UV map isn't scaled quite right just yet, so we'll tweak it a bit:

image image

I just scaled up the UVs, and moved them a little:



I find this technique substantially easier than trying to transform the UVs after the fact, and it's much easier than using UV Edit Pro.

An easier way to make Trekkish ship hull "Aztec" patterns

I'm always on the hunt for cheaper and easier ways to do things. If you're a Trek nut, you've probably given the special effects of the various movies a good hard look and noticed some exquisite texturing of the ship's hull. A fine example of a fan's work can be seen here. The thing to note is the repeating pattern of light and dark areas on the primary hull. Man, what a lot of work.

I found this site which had a pretty good tutorial on how to achieve the effect with fairly low effort. Low effort? Yah, right. It still was more than I wanted to invest. For starters, I haven't got enough experience with Illustrator to get the lines all lined up, and curved, and properly radial. Blek. I decided to come up with a trick that exploited the power of Lightwave (well, any 3D rendering app should be able to achieve the same results) and avoid even more work.

  • Lightwave can make cones.
  • Lightwave can project bitmaps onto surfaces using "cylindrical" mapping.
  • Lightwave can render orthographic projections.

Are you thinking what I'm thinking? I can make a pattern in just a few minutes. As in, perhaps five whole minutes.

Start up your favorite paint program (that can paint individual pixels) and make a very small bitmap. Black and white, 7 pixels across and 6 pixels down. I used Windows Paint. Paint a pattern of black and white pixels that has no intrinsic pattern to it and has a roughly 50-50 distribution of black and white. Something like this (It's zoomed in for clarity - those are really just single pixels):

Now, make a new bitmap that's twice as tall and four times as wide. Copy your base image into the upper-left corner. Then paste your base image again into the lower left corner. In the lower left, invert the black and the white (Windows Paint has no automatic feature to do this):

Now, Copy those pixels and drop them adjacent, and flip them left/right (Windows Paint does provide a method to do this automatically):

Now copy the pattern from the lower left to the upper right, and vice-versa:

We're now ready to exploit Lightwave. Save this image. Start up modeller and create a cone, on the Y axis, 500mm radius for all dimensions. Initially, give it a low number of sides, but we'll change that later. For the default texture, make an image map, cylindrical mapping on the Y axis, and use the little bitmap we've prepped. Turn off pixel blending and mipmapping. Click Auto Size. For the scale, set Y to 1/N, where N is how many concentric "stripes" you want (X and Z scale should already be set automatically). Set the Width Wrap Amount to how many radial repetitions you want. Save the object and start up Layout.

Load the cone into a new default scene. Change the default light to point straight down, and move the camera so it also points straight down, and then aim it over the cone. You may need to increase the light's intensity to get black and white results, as opposed to black and grey. Set your camera resolution to something square. If you're using Lightwave 9, set the camera type to Orthographic, and set the image height to 1m. If you're using an older version, set your camera very high up, and then zoom in so the cone occupies the whole image view. Render!

You may notice that yours doesn't quite look "round." This is because the cone isn't quite round. Go back to modeller and recreate it, only this time give it 1000 sides. That will make the base of the cone round enough that you won't end up with a pointy edge and an angular feel throughout the pattern.

I don't know about you, but I say that's a whole lot easier than playing for an hour in Illustrator. Of course, you might want a bit more control over exactly where things fall, and you may want a different pattern closer in to the center. This will take a bit more work, but you can easily figure that out on your own (slice the cone and define more surfaces).

A cheap way to make a geodesic dome

I've been paining myself on how folks have made geodesic domes. It seems like an awful lot of work to do, and it must be pretty difficult to get everything all lined up. Then it occurred to me that Lightwave Modeler has all the necessary tools to do this quickly and very easily.

Here's a quick cheat-sheet recipe:

  1. Open modeler and select the new Ball tool. Open the Numeric panel and change the type to Tessellation. Leave all the defaults alone. Close the tool.
  2. Select the bottom half of the sphere and delete it.
  3. Select all the polygons and change the surface name to Beams.
  4. Select the Bevel tool and open the Numeric panel.
  5. Apply a bevel of 1.25mm shift and 1.25mm inset.
  6. Apply another bevel of -1.25mm shift and 1.25mm inset.
  7. Apply another bevel of -1.25mm shift and -1.25mm inset.
  8. Apply another bevel of 1.25mm shift and -1.25mm inset.
  9. Change the surface name to Glass.
  10. Deselect all polygons.
  11. You're now ready to apply appropriate surface attributes to the beams and glass.

Presto! One geodesic dome!