bpy | blender python scripts | Addon library

It turns out, that the problem was the execution context. This became clear after invoking the timed event manually, e.g. after the scene was loaded completely the timed event was still executed in a wrong context.

Since the crash happened in the add_curve_spirals addon, the solution was to provide a context override the the operator invokation. The rest of my script was not equally sensitive to the context and worked just fine.

It was not clear to me, how exactly I should override the context, but this works for now (collected from other parts of the internet, so I don't understand all details):

See the documentation for using channel layers outside of consumers

primitive_add_cube is an operator, which causes a scene update. The more objects you add, the more has be to updated after every addition. So it becomes exponentially slower.

You should avoid that by using the low-level API. If you want to add the same mesh (cube) again and again, simply copy the object. If you don’t be this to be a linked duplicate, also copy the mesh data:

After loading R and T try this and use quaternions for camera direction.

print returns None. Just use result = i.name.split(".")[1] instead. And no need to convert it to string afterward. So this would suffice:

Is this what you want?

If ICameraInfo does not have FriendlyName property that you want and you must get the actual value from an indexer property, I don't think that DisplayMemberPath is the way for you to go. Instead, you should probably layout the ItemTemplate for your ComboBox and in it, have a TextBlock that pulls the string value. You could even use a converter for this if necessary. For example, something like this:

I found the solution! If you paste

I'm not quite sure what your goal is but to "flatten" the vertices sounds like a projection operation where you need to transform the vertex positions so Z equals zero. For that you could calculate the face orientation of the triangle and rotate the triangle vertices by the negative of that. But then it is also unclear what the significance of the local offset is around which that rotation would takes place. You could try to elaborate on the result you want to achieve, the source data you're working with or your attempts on it so far since the solution might as well be just ignoring the Z value of the triangle vertices when exporting if they're already provided aligned flat to the plane of the X and Y axis.

Adding answers from the comments below:

1: To rotate the triangle around its center point P where P is the average position of the 3 vertices (V0+V1+V2)/3 and the rotation R is derived from the face normal which is calculated with the dot product of the vectors V1-V0 and V2-V0 as elaborated here https://stackoverflow.com/a/1516330/15786521 the vertices need to moved by the negative of P, rotated by the negative of R and then moved back by P or in matrix operations where V is a vertex position:

V' = V x M(-P) x M(-R) x M(P)

The problem though is that rotations don't commute, meaning that the outcome of rotating around the X and then by the Y axis is not the same as rotating it around Y and then by X. In your case rotating around the yaw, then pitch, and ignoring the roll might work but I can not tell which way would best suit you since the resulting roll of the triangle would differ if you rotated by the pitch first for instance.

2: If you simply want to map your triangle on a texture or the like where only the proportions matter and the 3d orientation is irrelevant since the goal seems to neutralize/flatten it then simply get the dot product and distances of the vectors V1-V0 and V2-V0 and construct your 2D representation of the triangle from that.