Technique for creating 3D models from real world objects


#1

Hi,

As a complete SketchUp newbie can someone describe the process by which one creates such accurate models of real world objects (as appear in 3D Warehouse)?

I do NOT mean the list of SketchUp commands.

Rather, I’m wondering, more generally, about the approach/technique of how modelers create such accurate reproductions.

For instance, do they take a gazillion measurements from the real object itself (tricky when one may not have it to hand) and then craft every last surface etc in SketchUp? Alternatively, is it possible to import a graphic image of the object into SketchUp and have it auto-recognize edges and surfaces as a starting point, that can then be further refined?

I’m operating under the assumption that there are some simplifying technique(s) for decomposing the work into something tractable.

Perhaps it is as laborious as taking hundreds if not thousands of measurements, I don’t know. However, the level of work for something even relatively simple seems extraordinary. Regardless, I would like to hear from modelers of real objects what’s their typical plan of attack.

Thanks,
Paul


#2

It depends upon what the object is. I make a lot of models based on existing pieces of furniture. I generally only have rough overall dimensions and a few photos. I use a variety of methods for working out the dimensions including importing the images, squinting with my calibrated good eye, and some deductive reasoning. For other models I have dimensions of every part and all the details. Sometimes I sit with a caliper or and take measurements or use a tape measure on larger projects. It all depends on the thing I’m modeling and what I have in the way of information.

No but you can import an image and trace over it.

It doesn’t have to be like that. It depends on what you know and what you need from the model once you’ve drawn it and how precise it needs to be.


#3

With an extension, the outline can be automatically traced.
@jimhami42 has a BMP tracer plugin.

But nothing so magical as inferring 3D from a 2D representation. This is only something that the sentient brain can do easily.


#4

Additional thoughts:If you are drawing something made up of multiple parts, it might seem intuitive to draw each one separately, maybe even in separate SketchUp files, and then move them together to make an assembly. This is possible but then you have to know many more dimensions to draw the parts.

I find it easier and faster to set out components that define the outer limits of the model and then draw everything else to fit in between. If the parts that define the outside are properly drawn and positioned, everything in between just needs to be drawn to fit. No need to know the lengths of those parts. If you want to know the dimensions, you can get SketchUp to tell you.

I can provide examples showing that process if you need them.


#5

I have been involved in a hobby project for the past four years or so using SketchUp to create a high-fidelity model of an actual object - the Viking '75 Mars Lander spacecraft. Two were launched in 1975 to Mars and both landed successfully in 1976. Here is a video I created last year about the process I use to create the digital 3D model. Here is an album of 2D images of the model, as a work-in-progress.

I am trying to faithfully re-create a detailed model with fairly high accuracy (on the order of a millimeter or two wherever possible). This makes the creation process very slow (for me anyway). After somewhere between 1000 and 1500 hours, it’s less than half done. :slight_smile: As mentioned in the video I’ve had the great fortune to visit a number of remaining Viking test hardware components in museums and captured over 1000 direct measurements (here are some examples), and I’ve taken about 3500 detailed photographs that I use for reference (here are some examples) to estimate dimensions where needed. I also acquired a set of assembly blueprints that have been very helpful for the core spacecraft body.

Here is a topic in this forum’s gallery section on the spacecraft components I am currently modeling.


#6

Thank you everyone for the great replies. They were very helpful!

As for Tom’s work on the Viking Mars Lander, well that just takes my breath away. Talk about a labor of love! Great work Tom!


#7

It’s often possible to obtain various 2D & 3D reference information from manufacturer web sites (often categorized under a ‘Professional Resources’ page). As mentioned above, there are a number of ways to work with images; Match Photo can be a useful method for getting started if you’re working off of a perspective image and at least one of the product dimensions (height, etc) is known. It’s also relatively common to find 2D CAD files in DWG or DXF format, that you can import into SketchUp and use as a reference. In other cases, you might be able to source full 3D models in a format that can be imported into SketchUp. Based on the quality of the imported file and whether the model is too detailed, or not detailed enough, you can then continue to make further modifications, add textures, etc.


#8

I do not think so graphic image of the object into Sketchup and have it auto-recognize edges.


#9

This topic was automatically closed 91 days after the last reply. New replies are no longer allowed.