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Topic: Clipping issues in orthographic views!!!  (Read 2886 times)

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  • Polygon
September 12, 2013, 11:46:27 PM
After working on relatively complex scenes that include many different objects (think an interior scene, for example) I found that NVil has some serious difficulties with camera clipping in (although not limited to) orthographic views.

This makes selecting of vertex rows of long objects like walls, pipes, etc. a very big problem unless the selection is done in perspective view.

I wasted lots of hours (and now have two days of delay) trying to find a solution to the problem. I tried altering near/far clip planes or using "Best Fit", "Set View Focusing Point", "Selection Focusing" and "Camera Focus Point (SEL)". Nothing helps to get rid of this horrible clipping.

Also, Steve suggested to set camera clipping to 0.1/100, but it causes to back wireframes to pop out if the ortho viewport is zoomed out too much, so on the video below I reduced the far clip plane to 10 meters.

http://youtu.be/7H6Eq2U3p6o

The scene from the video is roughly 3.1 x 2.3 x 4.7 (XYZ) meters in size and the object visible is on the far end of the -Z axis.

Such clipping doesn't occur in other 3D programs unless I deliberately force it by adjusting clipping values or moving orthographic cameras.

http://youtu.be/5XotBAsdYzM

One solution to this problem I can think of is to use "physical" cameras for orthographic views. Cameras that are visible in the viewport, like in Maya for example. In this 3D package, if you move the ortho view, it translates in the world space. If you zoom in or out, it scales up or down (this one is a little bit misleading, because you can scale the camera's transform node without any effect to zoom. This is handy when scene scale is large and camera shape too small to be visible). You can manually translate it in perspective view wherever you want, so you can clip unnecessary geometry without even altering the clip attributes of the camera.

Please IStonia, do overhaul NVil cameras. In the current state, I find NVil to be almost completely unusable because of this issue.

P.S. Also, I've noticed that "Set View Focusing Point" doesn't always work. As you can see on the video, I hit the keybind that invokes this command, but nothing happens.

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  • Polygon
September 13, 2013, 07:58:24 AM
Can you send me the scene file and all your config files which are located at C:\Users\UserName\AppData\Roaming\DigitalFossils\NVil\User Settings. To info@digitalfossils.com.

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  • Polygon
September 13, 2013, 03:34:45 PM
Hello IStonia.
Of course, I'll send it ASAP. Thanks.

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  • Polygon
September 13, 2013, 05:07:19 PM
Mail sent.

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  • Polygon
September 16, 2013, 12:48:12 PM
Hello IStonia.
Did you perhaps found some time to take a look at the problem?

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  • Polygon
September 16, 2013, 08:53:27 PM
I have already got it done. The new update will be available in about a day.

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  • Polygon
September 16, 2013, 10:44:31 PM
Wonderful news IStonia! Thank you for fixing the issue in such short notice. I can't wait for the update.  ;D

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  • Polygon
September 18, 2013, 11:39:49 AM
It should be better now.

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  • Polygon
September 18, 2013, 01:38:57 PM
Hi IStonia,

It should be better now.

I do not understand the direction you have taken with this.
If a fix to this problem had been simply a case of increasing the far clipping plane, then it would of been a lot easier to inform the user to increase the far clipping plane, or simply change the default from the current 100 to 1000 or even 10000. But that is not the case, as the problem is based around the ortho views.

A simple example:-

Create a simple box of 1x1x1. Change view_port layout to 2 views, making one of them "Front orthographic" and the other "Custom/Perspective"

(UI reduced in size for screen grabs)



Perform a (obj mode)"Best Fit All", which appears to be OK. Selecting(MMB window select) the corner vertex from the "Front ortho" view, does in fact select both front and back vertex as expected


Now, increase the size of the box to 100 on Z and again [obj mode)"Best Fit All"
This time, in the front ortho view, the object almost disappears into the distance.(I hid the manipulator, otherwise you would not see the object at all in the ortho view)


So of course, to see and select sub_objects on the object in the ortho view, there is a need to zoom in. However, as you zoom in to get the object to a reasonable size the camera as made dolly into the object, so when you attempt to select the vertex, it will only select the back vertex.



You can workaround that problem by selecting the front polygon and then zoom to fit, but should that really be needed?

If instead you use an added camera for the ortho view, you do not see that problem, as the camera will zoom the view rather than dolly the camera position.

.

« Last Edit: September 18, 2013, 01:41:41 PM by steve »

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  • Polygon
September 18, 2013, 02:35:37 PM
Yes, I agree with Steve. The problem seems to be only halfway solved. While I can select distant components in orthographic views now, the near clipping still occurs. The more you zoom in the orthographic view, the more near clipping you get. It's almost like it isn't zoom at all, but camera dolly.

And what Steve said, there is already camera implementation present in NVil (Geometry->Create->Add Camera). If I add it to the scene, position it properly, scale it up to ensure that far clip plane encompasses the whole scene and set this camera to orthographic mode, I can zoom in or out without any clipping at all. This is how orthographic camera should work.
« Last Edit: September 18, 2013, 02:37:53 PM by rubberDuck »

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September 20, 2013, 08:42:29 AM
Hopefully the new update has fixed the problem.

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  • Polygon
September 20, 2013, 09:22:09 AM
I can still create an anomaly(when creating an ortho view inside an object.) But not (IMHO) enough of a problem to make further changes.

It does appear to fix the issue posted.

Many thanks for getting the new fix out so quick.

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  • Polygon
September 20, 2013, 10:53:41 AM
I did some quick tests too and indeed, the problem appears to be fixed now.
IStonia, I can't thank you enough for patching this up! :D

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  • Spline
September 30, 2013, 11:22:14 AM
Thank you so much for looking into this.  I've had loads of issues along the lines of those posted in this thread in the past.  I create a lot of characters in the course of my work and I'm always creating small highly detailed objects being worn on a (relatively much larger) human-sized figure.  Also, I work at 1:1 scale in millimeters, since most of my models are for 3d printing.  For some reason, that combo has always given me grief with the clipping planes in Nvil as I was constantly have to refocus on individual polygons.  I haven't used the 20Sep13 update yet, so I'm looking forward to seeing if it makes life easier.  Will report if it doesn't.  Cheers.

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  • Polygon
August 11, 2014, 10:01:18 PM
Same problem again. It's been a long time since I last experienced it. Turns out it didn't go away forever. 2014-Aug-02 version: :-\

https://www.dropbox.com/s/lhn2rumouo0imys/ortho_clipping_again.mp4?dl=1