>I presume the iges file is really large?

45MB, 95,000 entities. It opens in Rhino2 and can be worked with. A bit jerky when translating but that's to be expected with this many parts updating.

>Are you willing to put it on a CD-ROM and snail mail it to me?

Possibly. I'll have to check with the agency.

>Switching to running extremely slow is generally a symptom of RAM being completely full and having hard-disk swapping engaging.

Disk was silent. Looked like a memory leak. Running 2GB RAM. Just opened the model with Task Manager pre-opened and watched the memory. MoI started with 23 MB with no model loaded. Climbed to 212.6 MB with the IGES file loaded. VM use climbed to 201 MB. CPU never got over 50% each on a dual CPU system while this is working but it did show 66/68 when it hung.

>But it is odd that it is triggered by zooming in. Is it when you zoom in especially tightly?

I'm zooming out.

>Curve drawing is actually a pretty intensive procedure, a lot of time it actually takes more crunching than surface drawing for many models.

I'm guessing that this is the case. When zooming out the front view, internal curves that couldn't yet be seen in the top view re-drew themselves many times. this time, I tried zooming out really fast and it got past the point where it would hang previously. Memory climbed only to 224.6 MB. Zooming the side port, memory climbed to 229.6 MB. Zooming the front port out made no increase over the side port value. As the zooms progress, they update faster when more of the model is outside the viewport. As more comes into view, the updates become chunky. A clue, here, may be that when zooming the front port this fast, none of the curves had a chance to redraw. Once it got out far enough to display the whole model, they are small enough that they do not display.

While trying to export to OBJ, the CPUs go to 50%x2 and the dialogs that show asking for parameters exhibit the same slowdown as when the app hung. While this is going on (selecting quads & triangles in meshing options) memory slowly climbs at ~100K/s. This one dialog selection took about 5 minutes to complete. Through all this, peak memory use was 273 MB, so I'd guess that running out of RAM isn't the problem but the app running around in circles internally might be.

The OBJ hangs Deep/3D Explorations at object 5648, so can't see if it has done this correctly. 3dm seems to only export Rhino3 files, so can't look at this either.

[later] I think I found something. When the model did open and zoom/translate successfully without pegging the CPUs, it was in wireframe mode. Creating new geometry while this model was loaded created non-shaded representations. Closing the model and creating new geometry continued to create nurbs wireframes. Closing the app, re-opening and loading the IGES file, loaded it in shaded mode and MoI crashes when zooming. Presumably, this is due to hidden geometry re-draw that partially shows through the shaded surfaces, so I turned off display of hidden curves and edges. Model will zoom out farther and faster but presents the Unexpected condition (crash) dialog instead of hanging. Question is, how did/do I get into/out of wireframe?

But then MoI crashed XP entirely to a black screen reboot, rather than closing when hitting the "Close" button in the Unexpected condition dialog. This also happened the first time yesterday, where the 2nd through 8th times it hung with no dialog presented and a finger was required to continue.