Modeling weld spots
by Daniel Buck
http://www.danielbuck.net/
This tutorial will show one way to model weld spots onto cylinders,
like a tube chassis for a vehicle, or anything where 2 metal pipes
are welded together in real life. Taking the time to model the weld
spots adds to the realism of the model, more so than 2 pipes just
"resting" together.

Start out with your pipes (cylinders) arranged where you want them
(intersecting).

now make a tube with about 18-30 sides, 1 cap and 1 height segments.
place it near where you want the weld to be around the pipe (I have
moved a copy of it to the center so you can see it)

turn the tube to an editable poly or mesh, and move the vertexes to
fit the intersection of the pipes.

basically, just move (from a side view) the vertexes to a "u" shape
to fit. Each different angle of the pipes will require you to adjust
the weld mesh to fit.

now put a mesh smooth modifier of 2 iterations. (2 usually works for
me). you can see that we have something that looks like a weld spot
now!
the only thing left to do now is to move some of the vertexes around
to get a "blob" look to the weld spot. click back to the editable
poly/mesh and start moving them around

you should get something like this (adding edges where you need more
blobs) the edited weld spot is on the right, notice that it looks
much more like a real weld spot than the one on the left.
you can probably get a decent shape using the noise modifier instead
of moving the vertexes by hand, but I like to have full control over
the weld spot to get the exact look I'm going for.

a wire view (with no mesh smooth)

rendered
There is always more than 1 way to model something, you may want
to try using a noise modifier to give the weld a random look. I have
also seen a technique that used particles to create the weld spots.
A note of caution, a scene with many weld spots can bog down Max
fairly quickly. you may want to back off to just 1 meshsmooth iteration
if this happens.
© Daniel Buck