Reverse engineering with Recap Photo

By Chris Smith

Introduction
At some point during our design processes, we can find we need a model that is not readily available to us. This model may only be for visualisation purposes or to ensure function or fit with another product. In this quick tutorial I will look at how we can quickly create inventor models using scan data, mesh, or surface model formats, like obj or fbx.

Recap Pro / Recap Photo
Engineers have the capability to create scan data from photographs using recap photo, which is part of the Recap Pro application available in the Product deisgn collection. Here is a quick example of creating a scan model with Recap photo.

First you will need images of the item you would like to model, the more images the better, although this is capped at 300 images. To create higher definition models, it is best to use a high performance camera with optimal lighting, to catch as much detail as possible. Reference markers can also improve the quality of the output data.
My example had 37 images, taken with a smartphone, in indirect sunlight and a polished, reflective surface. So not ideal conditions.

Once you have selected your images, Recap pro works in the cloud to create your scanned surface model. You will need cloud credits for this.

Within a few minutes my model is returned from the cloud.

Using the lower right icon, I can open the mesh file to see the results.

Below are the results that I achieved with very little details supplied.

I can then export the model from Recap Photo to use in another package that will allow me to refine the mesh model. Fusion 360 has this capability and is also part of the Product design collection suite of tools.

Fusion 360 mesh conversion
Below is our recap model in the Fusion environment. I can use the surface and mesh tools in Fusion 360 to remove all the excess data that I do not need and refine the surfaces for use in creating a model.

As my scan is very low quality, I will use a different option and download a complete surface model from a sharing website.

I can import this obj file into Fusion 360, just as we did with the photo scan.

Next, we need to define the faces of our mesh model to convert them to surfaces. Fusion 360 has an automatic face tool that we can use called Generate Face Groups.

Once the face tool has completed its task, we can see each face that has been recognised by the different colours shown. There are still some mismatches that we need to resolve, as you can see with some faces having different colours, like the front curved surface.

We can fix this by grouping faces together with the Combine face groups tool.

We can also use the Create face group tool to define our own face boundaries by selecting the facets of the mesh we want as a single surface. Opening the Mesh Selection Tool from the selection menu will allow the use to change the brush size.

Once we have tidied up our surfaces, we can move on to converting the model. The image below shows a more uniform colour on all faces.

Using the Convert Mesh tool in the Modify flyout menu, we can convert the mesh surface model into a solid model.

For my model I am going to choose the prismatic option, as this option will aim to keep any sharp edges. A more non-uniform, flowing shape would suit the new Organic solver and simple scan data will suit the Faceted solver.

My mesh model is now converted to a solid model.

Exporting the new solid model
I can export the model from Fusion 360 as several different file options.

I will export the model in Inventor native format (ipt).

Opening the file in Inventor I can change a few appearance settings, and now I have a reference model to use in my designs.

Having the capability to reverse engineer scan data can really help when it is difficult to get access to the original model files. Autodesk Product Design Collection gives engineers the tools to overcome these difficulties, you just need to know where to look.

I hope you found this short tutorial useful. If there are any other areas that you are having difficulties with, please do not hesitate to contact the team here at Cadline.