Is there a way to properly save a ComponentDefinition to an .SKP file?

Mitchell2.24v · March 1, 2021, 1:31pm

Hi All,

I have been struggling with this for a while now. I’m trying to recreate the Save Local Collection functionality as found in SketchUp in my own code using the C SDK. As far as I can tell there is no function to directly save a ComponentDefinition. Creating an instance and saving that results an extra level of nesting in the saved SKP file.

Is there any way I can take a ComponentDefinition and save that to a file?

Thanks in advance for your suggestions!

dezmo · March 1, 2021, 2:02pm

I don’t know the C API, but I remember reading something like that somewhere … maybe you can check it out here:
https://github.com/SketchUp/api-issue-tracker/issues?q=is%3Aissue+is%3Aopen+save++label%3A%22C+API%22+

Mitchell2.24v · March 1, 2021, 2:36pm

Thanks, I had already combed through the issue tracker, but couldn’t find a usable solution there.

DanRathbun · March 1, 2021, 5:29pm

Not currently as it is missing from the C API:

Yes, and worse, … it is bugged:

github.com/SketchUp/api-issue-tracker

SUComponentInstanceSaveAs modifies the original instance and makes it unique

opened 03:54PM - 04 Oct 19 UTC

closed 03:51PM - 08 Feb 22 UTC

AnFunctionArray

bug wontfix C API SketchUp logged

The issue is that SUComponentInstanceGetTransform always returns identity when r…equesting on a parsed component instance from a [model skp file](https://forums.sketchup.com/uploads/short-url/aWMKUyX8PiMCa4IAIGC2CnaCjyn.skp). Consider the following code: ```cpp #include <stdio.h> #include <iostream> #include <SketchUpAPI/common.h> #include <SketchUpAPI/geometry.h> #include <SketchUpAPI/initialize.h> #include <SketchUpAPI/model/model.h> #include <SketchUpAPI/model/entities.h> #include <SketchUpAPI/model/face.h> #include <SketchUpAPI/model/edge.h> #include <SketchUpAPI/model/vertex.h> #include <SketchUpAPI/model/component_definition.h> #include <SketchUpAPI/model/component_instance.h> #include <SketchUpAPI/geometry/transformation.h> int main(int n, char **args) { // Always initialize the API before using it SUInitialize(); if (n > 1 && !strcmp(1[args], "display")) { SUModelRef model = SU_INVALID; SUModelCreateFromFile(&model, "new_model.skp"); SUEntitiesRef entities = SU_INVALID; SUModelGetEntities(model, &entities); size_t count = 0; SUEntitiesGetNumInstances(entities, &count); std::cout << "instance count: " << count << "\n"; SUComponentInstanceRef* instances = (SUComponentInstanceRef*)_alloca(count * sizeof * instances); size_t szinstances; SUEntitiesGetInstances(entities, count, instances, &szinstances); std::cout << "returned instances count: " << szinstances << "\n"; while (szinstances--) { struct SUTransformation matrix; SUComponentInstanceGetTransform(instances[szinstances], &matrix); struct FloatingPosition { double x, z, y, d; } pos = { .x = matrix.values[12], .z = matrix.values[14], .y = matrix.values[13], .d = matrix.values[15] }; printf("%f, %f, %f\n", pos.x, pos.y, pos.z); } return 0; } // Create an empty model SUModelRef model = SU_INVALID; SUResult res = SUModelCreate(&model); // It's best to always check the return code from each SU function call. // Only showing this check once to keep this example short. if (res != SU_ERROR_NONE) return 1; // Get the entity container of the model SUEntitiesRef entities = SU_INVALID; SUModelGetEntities(model, &entities); // Create a loop input describing the vertex ordering for a face's outer loop SULoopInputRef outer_loop = SU_INVALID; SULoopInputCreate(&outer_loop); for (size_t i = 0; i < 4; ++i) { SULoopInputAddVertexIndex(outer_loop, i); } // Create the face SUFaceRef face = SU_INVALID; SUPoint3D vertices[4] = { { 0, 0, 0 }, { 100, 100, 0 }, { 100, 100, 100 }, { 0, 0, 100 } }; SUFaceCreate(&face, vertices, &outer_loop); // Add the face to the entities SUComponentDefinitionRef def = SU_INVALID; SUComponentDefinitionCreate(&def); SUEntitiesRef defentities = SU_INVALID; SUComponentDefinitionGetEntities(def, &defentities); SUEntitiesAddFaces(defentities, 1, &face); SUComponentInstanceRef instance = SU_INVALID; SUComponentDefinitionCreateInstance(def, &instance); static SUTransformation matrixtransform; constexpr SUVector3D point = { 666, 666, 666 }; SUTransformationTranslation(&matrixtransform, &point); SUComponentInstanceSetTransform(instance, &matrixtransform); SUEntitiesAddInstance(entities, instance, nullptr); //comment the next line to make it work SUComponentInstanceSaveAs(instance, "instance.skp"); // Save the in-memory model to a file res = SUModelSaveToFile(model, "new_model.skp"); // Must release the model or there will be memory leaks SUModelRelease(&model); // Always terminate the API when done using it SUTerminate(); if (res != SU_ERROR_NONE) { std::cout << "Unable to save document!"; return 1; } std::cout << "Document saved!"; return 0; } ``` I'm using SDK_WIN_x64_2019-2-222. The above code will always print 0.000000, 0.000000, 0.000000 - component_instance_name - no matter if the component instance have any transformation taken in place (I exported them to skp with a transformation).

I am sorry but there is no workaround that I can come up with. We might have (been able to kludge a end around) if the C API had an explode function, but it does not.

This issue is at least 4 years old now, and IMO is the worst glaring C API omission and bug outstanding.

Completely recreating all the definition’s entities within a new model is likely to be quite tedious codewise.

I might also suggest you build your component’s entities in a separate model object and save them out to a component file(s) and later load them with SUModelLoadDefinition, rather than building them within a model’s definition collection.

Mitchell2.24v · March 2, 2021, 7:46am

Thanks Dan, for your detailed reply (as usual ).

I have been searching for an explode function and couldn’t find anything like it. So your confirmation is both good to hear and a bit disappointing.

The two issues in the tracker had caught my eye as well; I was hoping to create something of my own that would mimic a SUComponentDefinitionSaveAs, but the C SDK is not complete enough to do so.

I even ventured into completely recreating the definitions entities, but that led to more problems than it solved. It can probably be done but is - as you put it - tedious so say the least. Testing it fully would also be a slight challenge.

In my current application the source for my component definitions is user created, so I don’t create the definitions myself, but I do need to same them to file individually. This lack of control over the content and quality of the definitions makes recreating them a gamble.

DanRathbun · March 2, 2021, 2:30pm

There is also no means via the C API to copy objects from one entities collection to another. (Also any supplied removal functions immediately invalidate the removed objects so they cannot subsequently be reused.)

All I can suggest is to add your desires and needs to the open issue(s) so as to supply a little “grease to the squeaky wheel”.

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Is there a way to properly save a ComponentDefinition to an .SKP file?

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