Zooming in- Model vanishes

monkeybss

I don't know why, but when zooming in on a certain part of the model,the closest part disappears.
It happens in models big and small, with or without hidden elements, no matter what kind of view (parallel or perspective)
I'm using Su 7.1 Pro on windows XP.
Can someone explain to me what I'm doing wrong? Or may be it's a bug in the prog?

mitcorb

This is a known "condition" related to model size(data), model scale, distance from 0,0,0 origin, and OpenGL(the display application)
It is called clipping. Search the keyword. A whole pile of information should pop up.
This is just an initial response to your question.
Others may follow.

thomthom

Models far away from origin will suffer from this.
Very large models will suffer from this (usually as a result of importing geometry in the wrong scale - unless you are modelling the Universe...)
Very small models will suffer from this - when the edges of what you model is only a couple of mm - that's too small.

You can try Zoom Extents - after turning on all layers and making sure Hidden Geometry is on.
Note that guidelines and guidepoints is not considered when SU Zoom Extents - so beware of any of these then trying to track down the cause of your camera clipping.

monkeybss

The problem is that I import the base for my models from Autocad and they are usually based on surveys, so that the origin point (0,0,0) might be very far.When importing to SU, I must keep the point of origin if I am to add elements from Autocad as the building develops.I guess there is no reasonable solution to the problem so far.Thank you anyway.

tridem

when occurs this, I used to change the view into perspective mode (perhaps with a very low 'field of view' value if you need more a parallel view)

thomthom

@tridem said:

when occurs this, I used to change the view into perspective mode (perhaps with a very low 'field of view' value if you need more a parallel view)

Not if his model is based on an AutoCAD drawing with world co-ordinates. Parallel camera is just one of the things that trigger the clipping issue.

smithryan07

When you are importing from AutoCAD using survey files they are often far from the origin. To compensate for this, create a new CAD file strictly for importing into SU. In the SU CAD file move everything as close to the origin as you can. Create a common mark in each CAD file, a line in the lower right hand corner of the file for example, to use as a reference point for lining objects up when importing from CAD to SU.
For example:: CAD-File-1 is in Real World Coordinates. Create a small reference line in the lower right hand corner and save.
Then, Save CAD-File-1 as CAD-2-SU-File. In this file move everything, including the reference line, as close to the origin as you can. Import this file into SU so that everything is close to the origin. Make sure to import the reference line with the file so that when you have to import items in the future you have a reference point to line things up.

In other words you are not relying on a coordinate system to line things up you are doing it manually.

I know this may sound confusing so if someone could help explain if they know what I'm talking about that would be great. Otherwise I will work on getting you some images to help out.

monkeybss

Thank you all for your advice. I think the solution with a second dwg file is the best for me, it gives me also the opportunity to get rid of all kind of unwanted objects.

jgb

This used to drive me nuts, till someone (Catamountain as I recall) gave me the solution.

When you get in close and clipping starts, highlight a face or line adjacent to the location you are zeroing in on. (why in a moment)

Then turn OFF Perspective view. (Camera-Perspective)

Your object will zoom way away from you as you have now reversed the clipping to out field.
Then zoom right in on the highlighted elements as a target, and you can get so close as to actually see the screen jitter. Easy on the mouse when in very close, as it will "hyper-pan/zoom" with ease.

When you switch on Perspective, again expect the object to jump away somewhat.

Krisidious

there are a few "cures" I use

save the area you want to work in as a component, then open another instance of sketchup and open the component and edit from there. go back to your model and refresh the component.
reduce the scale of the entire model, I find that large models don't allow you to work on minute details.
make the area you want to work on a group, scale the group up using a relative scale 1'=1" and then edit the group, then rescale the group back to the normal scale.
make sure that your snapping and unit size are the smallest possible unit. or relative to the size of model... IE foot units for developments and large models, inch units for single family homes etc etc...
yell and rant at the clipping gods!!!!

jgb

@krisidious said:

there are a few "cures" I use

reduce the scale of the entire model, I find that large models don't allow you to work on minute details.

yell and rant at the clipping gods!!!!

The main problem with #2 is if any edge element becomes much less that about .005 inch (real measurement) it causes the bounded face to destabilize, and it cannot be reformed as a face due to "open loop" syndrome.

I used #5 a lot too, till I discovered the Perspective solution. Now, not so much.