sweep

Use the variable section sweep option.  When defining the sketch create a relation for dimensions in the sketch (the variable "trajpar" is the trajectory from 0 to 1).

Here is a 100 mm round sweep cut followed by a shorter sweep with the relation "sd3=100-(trajpar*100)" (sd3 being the radius dimension).  A carefully created relation could do it all in one feature.

I do not see the sweep feature clearly on the SW version.  If you attach the SW file, I can see what it is doing and do the same with Creo for you.

You can do this with a curve and the round feature. Create a sketched curved along one of the faces you want your curve, straight line the 3 point tangent or what shape you require. Create a round thru a curve, select the curve first, then select References and select the edge the curve will pass thru, and your done.

As always, it depends on the actual SHAPE you want.  You could try a VSS using a curve on a plane thru the edge, at half the included angle to control the radius going from a value to zero.  that way you can use an "S" shape at the end to make that last transition tangent to the radius dimension, to tangent to the edge.

We are just doing this to simulate the exact SW geometry, right? I mean... as a purely academic exercise? Did the original poster really need this exact, precise piece of geometry or was he just trying to do a simple round with a transition at the end? I'm just trying to understand for my own knowledge. The way I read the original poster's message, he's just saying "I can do this in SW as a sweep, can I do it in Creo, too?"

On the one hand, I was able to generate something exceptionally similar using "a simple round" with a variable radius and a transition. But I think it was hit on the head when he said "As always, it depends on the actual SHAPE you want." Are we just aiming for a round along part of an edge that tapers to a point? If so, mission accomplished in 15 seconds without a sweep, no trajpar, no complicated boundary conditions, and one simple(-ish) feature. But if we're actually trying to completely mimic this SW geometry, then I suppose understand this thread.

The SW geometry seems to have complete tangency nowhere along the triangular patch except at the edge where it intercepts the 15mm round. It surely isn't tangent along the two edges tapering into the point. On the Creo side (using the simple variable round), there's no tangency along that intercept edge - but there is tangency along the two edges. See below... (click for larger image).

Or, perhaps I've just "lost the plot"?

Thanks!

-Brian