Paint Coverage Idea, Is this possible with iLogic or Add-in?

[jake_egley]

Hi guys. I want to make a tool that simulates a part being painted and calculates the surface area that gets painted, as well as displays the part with the painted areas. The reason for this is that my company paints a lot of sheet metal parts, and we have to manually calculate the surface area of a part that can actually be painted (since some parts/assemblies have overlapped surfaces, or flush surfaces, closed hems, etc.) in order to accurately cost painting and order the right amount of paint. Right now we are just using the measure tool and making a judgement call as to which surfaces can get painted and adding them up. Everyone has their own way of doing it but it takes time and is not consistent. I want to make the process accurate and consistent as well as save time and effort. This is my plan for the tool. Can you let me know if this is possible to code with iLogic? or should I try to make an add-in? My knowledge of inventor API is very limited. Thank you.

(works on parts or assemblies)

1. Create Mesh

• for each surface create nodes that cover surface
• user to specify node size

2. Project Vectors

• at the center of each node project vectors in all directions from normal to 90° to normal
• vectors to be equally spaced in all directions. number of vectors at each node to be determined by trial

3. Check Vector Collision

• for each vector check if it collides with any part body
• if it does collide with any part body add it to a counter for that node
• counter determines how many vectors at the node hit part body and how many dont

4. Sum Vectors for Each Node

• if more than X vectors at the node collide with part body consider the node un-painted
• X to be determined in trial. Could start with 75%.
  

5. Calculate Surface Area

• Sum the surface area of nodes that are painted and un-painted

6. Create a Simulated Painted Part

• Make a new part that is a copy of the current part/assy and extrude each node .0001
• apply an appearance to each painted node
• display original iproperty surface area, painted surface area, and unpainted surface area.
• display transition zone (nodes that are +/- 5% of X show a gradient of the appearance)

If something is unclear please ask about it. Thanks for any direction you can give me.

[JelteDeJong]

Did you have a look at the "Finish Feature" introduced in Inventor 2024?

I think it does what you want out of the box.

https://www.youtube.com/watch?v=mH3jDeuwHvs

https://blogs.autodesk.com/inventor/autodesk-inventor-finish-feature/

[jake_egley]

Hey Jelte. Thanks for the response. We are on Inventor 2022 but after looking into the Finish Feature it does not appear to do what I am looking for. The part of 'finish feature' where you have to select the face to apply a finish to is the process that I want to automate with my tool. I don't want to select the face, I want the tool to automatically select all outward faces (and exclude the inside faces) that will get painted in a paint booth. Basically we make assemblies that may contain 20+ parts (usually sheet metal) that all get welded together and then the whole assembly gets painted as a unit while conveyed thru an automatic paint booth. There are surfaces such as the mated surfaces in the assembly that physically can not receive paint but will contribute to the total surface area calculation when you take the iProperty surface area. If we used the iProperty surface area we would be significantly over-estimating the amount of paint. Instead what we do is  manually select each exterior face with the measure tool to get its area (making a judgement call if that surface will actually get paint or not) and then add all those areas up. Could take 5 minutes to calculate the paintable surface area of a part or assembly. If the 'finish feature' does do that and I'm not seeing it that would be awesome.

[mat_hijs]

You could probably write a simple iLogic rule that will get all the A-side faces and apply the finish feature to them. If necessary you could do the calculations to determine which of these faces should be left out, at least if you can properly define what makes a face paintable or not paintable.

[jake_egley]

What do you mean by the A-side faces? The point of the rule is to automate the process of defining the paintable faces. I want to use a simulation method that checks every point on the part to see if it is covered by other parts or not. There are transition zones where some paint will hit a surface and thats why I want to project vectors and do some trial and error to determine where the threshold is for obstructed surfaces. Consider the basic example below: a 2" OD tube that is 1" long vs. a 2" OD tube that is 30" long. On the 1" long tube the entire inside of the tube will be painted and you can use the iproperty surface area as the paintable area. As the tube gets longer it is harder to paint the inside. On a very long tube if you use the iproperty surface area it will be about double the area that is actually paintable. And there are all lengths in between. This is just a basic example, we dont actually paint tube but all sorts of complicated geometry that is not easy to calculate. Hence why I want to make a tool that creates a mesh and does a calculation at every point.

I added a pic to the main post to illustrate my idea of projecting vectors to determine what points on each surface are paintable

[mat_hijs]

For some reason I assumed that you were working with sheet metal. With sheet metal you can define one face to be A-side and all tangent faces are then also A-side. This doesn't seem to be useful for your case though. Unfortunately your idea goes way above my programming skills.

[liminma8458]

To my experience, there is not universal tool painting area calculation. It is impossible to accommodate so many limitations impulsed by variation of products. I have a program to calculate outside painting area of power transformer. I have to bring in some pre-setup to make sure what area should be counted and what others should not be counted.  

[jake_egley]

I guess my idea comes down to if its possible to project vectors at a point on the purpose of a part and check if those vectors collide with part body. Could maybe use extrusions or lines instead of vectors