How to set tessellation control parameters

[MK_10060470]

I have the set tessellation parameters as below:

• step size is assigned with model size ( diagonal of the bounding box ) / 30.
• chord height is set by fetching the model accuracy using the GetAbsoluteAccuracy() method.
• Angle control is set to 1.

I am not getting a better result using this. The quality and the curves or circles in the model are not accurate.

I am using creo parametric object toolkit version 8.0.2.

[remy]

Hi 

You need assistance in setting Creo OTK to tesselate a model.
First can you confirm your application export to STL indeed?
If yes, have you found the settings that you need from the User Interface.

Reminder: Toolkit relies on existing UI commands. Once your UI command workflow is defined then you have your footprint to code.  

[MK_10060470]

Upon exporting the model in STL it's working fine.

[MK_10060470]

Please explain how to export each part in an Assembly with optimal tessellation values for parameters - step size, chord height, and angle control.

Do I have to do any additional computation to obtain the optimal result using the creo object toolkit?

[remy]

If I understand your request correctly, you are asking 2 things. Let's break them down:

1. Exporting all parts of an assembly:

The Export method needs to be called recursively. To perform that your application will need to list all component by calling ListItems() method and filter with type ITEM_SOLID_GEOMETRY and then list again and decide whether to recurse and so on. When hitting a leaf, then Export there and continue.

This will create one STL per model though. Is this what you meant by " export each part in an Assembly "?

2. Getting "optimal" tessalation for each part: define optimal because something can be optimal for some context and not for another. Now again, how do you translate optimal tesselation with UI commands?

for example do you mean a minimum number of triangles with no regards to the overal shapes and sizes? or do you require isocele triangles for nice looks and more regular meshing for downstream simultation for example?

My personal recommendation:

start with tesselating a part then tackle the recursing thing.

Search the internet if you need a crash course on recursivity (one of the fundamentals for example is to set the recursing ending condition early in the design of your algorithm (and prevent infinite loops)).