i got this message from time to time and the geometry lines dissapear until the next action in the drawing (the dimensions and notes are still visible):
This view has been frozen because of illegal view instructions.
Does anyone knows what this means?
I have interpreted it to mean that some or all of the geometry references that oriented the view are missing. Someone picked a face or an axis as a way to control the view orientation and now that feature is missing; either suppressed or deleted. It's always best to use default datums as the primary choice, but sometimes that's not applicable, such as creating a view that is normal to a surface.
this being a projection view, you suppose that the message refers to the parent view, the main view? But the "invizible" geometry is on the projected onw, not the main view.
It could be the feature that was used as the projection reference is no longer there. In looking at Google results, ways that some users get this is either by using insert mode which supresses a referenced feature or by converting a solid part to sheetmetal which may replace (replaced? some of the search results are over a decade old) most of the surfaces with new surface IDs.
I don't know for certain what Creo uses to determine orthographic projections, but I thought those were transforms of the original view matrix and should succeed unless the base view also has an error.
I would expect that the underlying process that any CAD system needs is to be given a vector that is normal to the screen/drawing as the primary orientation and then another vector that is projected on the screen to clock the view. If that second vector is zero length or non-existent, then that would generate an error. Since it's a calculation it's possible to have an error in making the calculation. In the case of non-orthogonal projections the second vector can be derived.
Could be as you say...
The problem is that is pretty random. And succeds on the main view sometimes. Which, I suppose, it was created with the basic planes...
Thank you for your time. It will remain a mistery, i suppose.
There are a lot of references maintained in view definitions that you cannot directly access. Since this falls under "corrupt data" in my book, I go through the lengths to fix it, up to and including deleting and redefining the view.
Stable references for view definition is something worth noting.
I have an example in creating true ISO views; I use geometry to set up a perfect ISO view.
I then delete the references; zoom the view; and save it. Now the view has no references other than the current orientation.