@box said:

I'm not sure what you are asking about.

If you are saying photomatch isn't working because the photos are different, then there's not a lot you can do about that. Photos for such things are never accurate, measurements and drawings are a better option. Photos usually only give you a way of checking exactely what is is you are trying to model.

I'm working with what I have available. Otherwise, there are options available to create great 3D models from reference pictures, they are just a bit more accurate than what I need for this project. Ironic perhaps, but true.

http://www.123dapp.com/catch

@box said:

There is no reason for accuracy being an issue, you can adjust the "accuracy" of the units in individual models, and you can work in larger scale and reduce down as needed.

I think where you will have problems is in the overall model. If you try to build the whole thing in one file you will overload SUs ability to cope.
Work on the individual pieces in there own files and only bring them together as needed in another file of components. For example, the engine block as one file/component and the pistons themselves as another. This way you work on the parts as if they are real. You can break it all down as small as you want, the valve stems separate from the valves if you want. But basically, make a library of tractor components then construct your tractor.

The problem is not the accuracy of the model. Note that I said I'm working with reference pictures and drawings... where I'm using photo match to create the model, but the model is not consistent to all pictures and drawings. Two sides of an engine block for example.

Otherwise, I'm aware of the limitations of Sketchup and plan to model separate sub-assemblies as individual models.

I'm attempting to create a 3D "parts model" of a tractor and most of it's individual components but have been having trouble getting it right. I have plenty of reference pictures and parts drawings to work from, but matching them accurately in Sketchup is anything but easy. So far, I've managed to create a reasonably decent looking 3D model of the engine (a work in progress) but the accuracy leaves much to be desired.

Keep in mind that what I'm trying to create goes way beyond a simple hollow shell, and is intended to have most of the internal components modeled as well. For example, the engine should have parts like the pistons, connecting rods, crankshaft, camshaft, etc...

Ultimately, I plan to utilize the 3D model to create illustrations of various parts and assemblies shown from various angles.

Suggestion or comments are welcome.