Graphics innacurate in 2022, jagged in 2024

[tpdes]

After getting fed up with lousy resolution of geometry in my models in 2022 Pro (components that are absolutely aligned appear to be woefully MISaligned, etc), I pulled the trigger and installed 2024.
Now, the components are sorta kinda aligned properly, but the rendering of surfaces has what I can only describe as ripped or torn edges. Sometimes like sawtooth, sometimes like waves.

I am using a Dell 3660 PC, 16 GB RAM, with an NVIDIA RTX A2000 Windows 10 Pro.

This is my model:
Close_WD.skp (746.4 KB)

This is what things look like in the 2022 version:

And this is what things look like in the 2024 version:

If this issue has been resolved before, Please point me to the solution. But I sure couldn’t find this exact problem.
Thanks all,
Thom

[Box]

Change your camera to Perspective.

[tpdes]

Thanks for the rapid response, Box. But I do not use perspective when I am aligning parts precisely. Maybe others get along with modeling in perspective, but I prefer axonometric projections.
You are correct, though, in that changing to perspective does fix the graphics issue. So I ask the SketchUp team: Why does it not work in parallel projection?

— 5 minute break to perform a test—

I just changed to perspective, adjusted the field of view to as close to parallel as possible. (It is unclear to me just what that means, but oh, well . . . so are many features of SketchUp.)
That’s almost bearable for me as a modeling environment. So the question I ask to the SU team still remains.

Especially when, after changing back to parallel mode, the textures and faces are repaired. Weird.

Seems to be a viable work-around, though. I closed the file. Reopened it. Textures and faces are torn. Change to perspective, then immediately back to parallel. Textures and faces repaired. Very strange.

Does no one else have this issue?

[Box]

Parallel Projection is really designed for static display, elevations etc and not for general modelling.
I know some people use it that way, but like you mention, perspective looks strange to you and parallel looks unbearable to us. As with anything it is what you first learn and expect to see.
The problem with working in PP(parallel projection) is that zooming is not realistic and the more you move around zooming in and out the more the camera gets messed up. You can be looking at something close up in PP but switch to P and you’ll find it is miles away from the camera.
The artifacts you are seeing are usually the result of modelling a long way from the origin, and so I would say it is related to that and how the camera position is be interpreted.

I believe @ateliernab also models in PP, perhaps he has seen this issue.

It could also be related to imported cad files, have you used anything like that? Because they can force an origin to be on the other side of the world.

[Elmtec-Adam]

I think I’ve seen this before.
Weirdly if you copy and paste it into a fresh file it all works as it should.
I wonder what causes this?

[tpdes]

Thank, Box.
Um … I’ve been designing buildings for more than 50 years. Most of that time, I used pencils, triangles, and parallel bars, and created “models” in two dimensions on paper. I “graduated” to CAD in the mid 1990s, I guess, when computers were more or less capable of calculating 3D models. (Actually, my first CAD experiences was with software that could ONLY render things in 2D. The proverbial “electric pencil.”

When we needed to impart images of the buildings, we used various tricks to render perspectives on (again) a 2D surface. I did some 3D modeling in AutoCAD Versions 9-14, then switched to SketchUp because I couldn’t justify the expense of AutoCAD. And I only bring up AutoCAD because in all the years I used that program, I never experienced any of these issues.

I treat CAD as a means of communication, not just to lay persons (such as are most clients) but to those in the industry who must saw the 2x4s and bang in the nails. The pretty picture of the completed structure has way less importance in that process than an accurately drafted (or modeled, if we must) depiction of the structure. I will argue that this process expands from houses to hospitals, factories, space rockets and cities, and zooms in on cabinetry, jewelry, machine parts, watch gears, nano machines.

SketchUp is a tremendous tool that does well in the mid section of that range, bogging down when we approach modeling entire cities, or N-scale railroad engines.

Sure, modeling in perspective “looks” like the real thing, kind of (it is still projected on the 2D surface of the monitor), but doing so is significantly more prone to errors in assembling a structure from parts, than performing the same assembly in parallel projection.

I am not a computer graphics whiz. But fifty years of making projections from ideas to paper and now to the monitor (which is then, sad to say, sent to . . . paper!), tells me that the process of how that’s done is one of choice. Choice by the developers of software, choice by the users of that software. No one has ever explained to my satisfaction why there is a necessary difference between the two types of projection.

To answer your final question, no, none of my model began as an import from another CAD platform. I model using native SketchUp tools and the occasional extension. I am super careful to place the origin of the models I create either ON an element of that model or within the model’s “bounding box”.

Thanks again.
Thom

[tpdes]

@Elmtec-Adam

I think I’ve seen this before.
Weirdly if you copy and paste it into a fresh file it all works as it should.
I wonder what causes this?

Adam, I don’t even need to do that. As I said to Box, merely flipping from parallel to perspective, then back, seems to restore all to acceptable appearances.
And actually, the ripped textures don’t bother me all that much–it’s really a matter of aesthetics–but the projection issues in 2022 that depicted what were carefully placed components as being way out of alignment was a REAL bother.

[Elmtec-Adam]

ah sorry, I misread this one.
Perhaps the problems are related, but manifesting themselves in different ways.

[Box]

Because you have come from the 2d paper/drawing aspect you may be fighting the premise of sketchup.
It is a 3d modelling environment with Layout attached for 2d construction documentation.
The inaccuracies you mention in 2022 are probably down to incorrect alignment in 3d space when viewed in 2d.
A very basic example.

[tpdes]

Adam, no problem. It’s handy to know there is more than one work-around to a problem.

[tpdes]

I have long ago given up fighting SketchUP. But I do use it, and rely on it, and appreciate its capabilities. I don’t think my experience with pencil and paper has any bearing on why SketchUp can’t project as adroitly in parallel as it does in perspective.

The inaccuracies you mention in 2022 are probably down to incorrect alignment in 3d space when viewed in 2d.<

I fail to understand how you make this assumption. EVERYTHING we see produced by SketchUP is 2D. Parallel projection is one means of viewing a three dimensional space. So is perspective. Both of them wind up on a 2D surface. Unless you have a holographic display.

Edit to add comment on graphic which was not in original response.
I believe that we all know that mistake. The solution for which was provided by SketchUp years ago by adding the arrow key restraints. Make two more graphics, one showing the two cubes in perspective and one showing the cubes in parallel projection. View them from above right as in the end of your little GIF.
No one would make the error you show by trying to join those objects in 2D. But I don’t need to argue with you about that. That is an error I haven’t made since 1993.

[Box]

@tpdes

I fail to understand how you make this assumption.

See the gif example I edited into the previous post.

Edit for your edit. I’ll leave you with it and not bother you again.

[Elmtec-Adam]

It’s good to know simply flicking it back and forth solves it.

Flicking it back and forth in 2022 solves the misalignment for me too there - a does choosing another scene.

So I’ve had a closer look and I see what the issue is - I don’t know how you got there but again perhaps lots of zooming in and out or a certain action made it happen?

Basically your virtual camera that you are viewing your model through (the viewport) has ended up approx 5,764,348 miles from your model- just a mere 25x further than the Moon is from earth.

And then you are zoomed right in - quite a zoom lens!

3d software freak out for various reasons when this kind of thing happens and lots of 3D packages won’t even do parallel projection because it is a warped version of reality. I’d always assumed that the model itself loses it’s precision at that distance and you get the strangeness happen, but perhaps it is simply SketchUp’s ability to show things correctly that is the problem.

It almost sounds like it was related to a bug that users exploited to create elevations - I wonder if you somehow induced that by accident.

[bmike]

@tpdes

Sure, modeling in perspective “looks” like the real thing, kind of (it is still projected on the 2D surface of the monitor), but doing so is significantly more prone to errors in assembling a structure from parts, than performing the same assembly in parallel projection.

I disagree with this wholeheartedly- I detail houses and timber buildings - some of them with nearly every Simpson clip and hanger and etc… it is far easier for me in SketchUp and perspective than in parallel. And I started on paper, moved to CAD and left it for SketchUp.

[PaulRussam]

I model in non perspective (I’m reluctant to call it parallel as I think that’s something specific) and then view/render in perspective.
I can’t bear the inconsistent zoom/orbit/panning in perspective when I’m here, there, everywhere as I build.
When I do have to work in perspective such as when I’m inside a nearly finished room and I need to move some furniture around for aesthetic reasons it drives me mad when I suddenly find myself in a wall/other room due to the inconsistency of the zooming.

I’ve never experienced the texture tearing mentioned in the original post unless I’m zoomed in to ridiculous degree to diagnose a vertex problem for example.

[ateliernab]

@PaulRussam

I’ve never experienced the texture tearing mentioned in the original post unless I’m zoomed in to ridiculous degree to diagnose a vertex problem for example.

same. both in perspective or parallel, I’ve only seen that when zooming on something like a madman. it’s like looking at the fabric of the universe.

as far as I’m concerned, the only visual glitch Parallel causes (when working daily with it) is the model partially being cut due to camera being too close. a zoom extent will fix that. other than that, modelling in one or the other is the same, no issues.

and to those saying “well actually sketchup was made to work in perspective and not isometric parallel” well yeah. it was also made to work in imperial not metric. and I recall reading that when working in metric, it actually converts in imperial. just because the original devs had something in mind doesn’t mean it’s divine law

[slbaumgartner]

It is a fundamental aspect of parallel projection that the size of objects in the view depends on viewing scale (aka magnification), not on the distance of the camera from them. The lines of projection are parallel (duh!), so moving the camera closer or farther doesn’t change how they hit the camera’s image plane. When you zoom the view in parallel projection, you are changing the scale factor, not the camera position.

Note that there is no physical viewing mechanism corresponding to parallel projection, though perspective projection through a very narrow field of view with the camera far away reduces the effects of perspective so that the projection looks more like parallel without actually being parallel.

Alas, SketchUp doesn’t always do a good job of handling this aspect of parallel projection as you manipulate the view using orbit, pan, etc. It is possible to get the camera very far from the model without realizing it. When this happens, the graphics system struggles to deal with the viewing calculations and generates strange artifacts such as you have seen. The graphics can also struggle if you move the camera very close to an object, as observed by @PaulRussam.

In contrast, in perspective projection the scale of the view does depend on distance of the camera from the object (as well as on field of view, focal length, or other notions of the lens properties). Changing to perspective causes SketchUp to revise the camera position in an effort to keep the size of the viewed object the same*. Then when you switch back to parallel, the repaired position is retained, fixing the graphics glitches.

* If the camera is effectively infinitely far from the model, SketchUp may be unable to fix it without help from a bit of Ruby code.

Edit: I looked at the OP’s model. The camera is almost 8 million feet from the model origin!

[DaveR]

@slbaumgartner

The camera is almost 8 million feet from the model origin!

Over 1500 miles (over 2400 kilometers) between the camera and the model it’ shouldn’t be a surprise that there’s graphics issues. This is a good example of why Perspective is always recommended for modeling and Parallel Projection just for scenes for static use as @Box wrote.

There are some exceptions for using Parallel Projection while modeling but as a general habit Perspective makes it easier.

[PaulRussam]

Typical model of mine:

HouseTypes:

Site:

Zoomed in:

Perspective View:

2P Enscape Render:

All one file, 327Mb, No visual tearing.
Su22, RTX2070

[slbaumgartner]

As a bit of historical perspective (I like to lecture, so ignore this if TLDR), I believe that parallel projection became the standard for technical drawings for two reasons that are independent of how we actually see things:

• The usual views are isometric and orthographic, meaning that the same scale applies to all edges in the view. You don’t have to deal with measurements that depend on the orientation and distance of things. You don’t have to deal with lines that are actually parallel looking non-parallel in the drawing.
• Parallel is much easier to draw by hand than perspective.

That said, parallel projection is a completely artificial presentation that does not correspond to how we actually see things or any physically possible way of generating an image. Light just doesn’t behave that way.

Like many others, I started out using parallel because I was originally trained to draw that way by hand and perspective seemed weird. But once I forced myself to try perspective for long enough to get accustomed to it, my opinion reversed, and now parallel looks peculiar to me, especially when orbiting a 3D object.