For the fun, a Photos cube

cvp

For the fun, based on topic
You can pinch for zoom, or move the camera by a finger or close the view with a 2-finger swipe-down gesture
Import 6 Photos, square if possible, in the same directory as your script.

from objc_util import *
import ui
import math

load_framework('SceneKit')

SCNView, SCNScene, SCNBox ,SCNNode, SCNMaterial, SCNCamera, SCNLookAtConstraint = map(ObjCClass, ['SCNView', 'SCNScene', 'SCNBox' ,'SCNNode', 'SCNMaterial', 'SCNCamera', 'SCNLookAtConstraint' ])

@on_main_thread
def demo():
    main_view = ui.View()
    main_view_objc = ObjCInstance(main_view)
    scene_view = SCNView.alloc().initWithFrame_options_(((0, 0),(100, 50)), )None).autorelease()
    scene_view.setAutoresizingMask_(18)
    scene_view.setAllowsCameraControl_(True)
    main_view_objc.addSubview_(scene_view)
    main_view.name = 'SceneKit Demo'
    
    scene = SCNScene.scene()
    scene_view.setScene_(scene)
    
    root_node = scene.rootNode()
    
    camera = SCNCamera.camera()
    camera_node = SCNNode.node()
    camera_node.setCamera(camera)
    camera_node.setPosition((-3.0,3.0, 3))
        
    cube_geometry = SCNBox.boxWithWidth_height_length_chamferRadius_(1, 1, 1, 0)

    Material_img1 = SCNMaterial.material()
    Material_img1.contents = UIImage.imageWithContentsOfFile_('Photo1.JPG')
    Material_img2 = SCNMaterial.material()
    Material_img2.contents = UIImage.imageWithContentsOfFile_('Photo2.JPG')
    Material_img3 = SCNMaterial.material()
    Material_img3.contents = UIImage.imageWithContentsOfFile_('Photo3.JPG')
    Material_img4 = SCNMaterial.material()
    Material_img4.contents = UIImage.imageWithContentsOfFile_('Photo4.JPG')
    Material_img5 = SCNMaterial.material()
    Material_img5.contents = UIImage.imageWithContentsOfFile_('Photo5.JPG')
    Material_img6 = SCNMaterial.material()
    Material_img6.contents = UIImage.imageWithContentsOfFile_('Photo6.JPG')
    cube_geometry.setMaterials_([Material_img1,Material_img2,Material_img3,Material_img4,Material_img5,Material_img6])
     
    cube_node = SCNNode.nodeWithGeometry_(cube_geometry)
    
    # Add a constraint to the camera to keep it pointing to the target cube
    constraint = SCNLookAtConstraint.lookAtConstraintWithTarget_(cube_node)
    constraint.gimbalLockEnabled = True
    camera_node.constraints = [constraint]
    
    root_node.addChildNode_(camera_node)    
    root_node.addChildNode_(cube_node)
    
    main_view.present(hide_title_bar=True)

demo()

abcabc

Nice. The following two lines could be added after cubenode definition if someone wants to animate the cube. (Also need to include SCNAction in the list defined after load_framework)

rotate_action = SCNAction.repeatActionForever_(SCNAction.rotateByX_y_z_duration_(0, math.pi*2, math.pi*2, 10))
cube_node.runAction_(rotate_action)

cvp

Thanks

I still try to define a shape like a tetrahedron (4 triangular faces) using SCNGeometrySource but I've problems with array of vertices.
I try to convert this code in Pythonista, I'm sure @JonB could do it in two minutes and I'm fighting against errors for hours.
My dream is to be able, one day in a very far future, to help JonB in something 🙄

SCNVector3 verts[] = { SCNVector3Make(0, 0, 0), SCNVector3Make(1, 0, 0), SCNVector3Make(0, 1, 0) };
SCNGeometrySource *src = [SCNGeometrySource geometrySourceWithVertices:verts count:3];
int indexes[] = { 0, 1, 2 };
NSData *datIndexes = [NSData dataWithBytes:indexes length:sizeof(indexes)];
SCNGeometryElement *ele = [SCNGeometryElement geometryElementWithData:datIndexes primitiveType:SCNGeometryPrimitiveTypeTriangles primitiveCount:1 bytesPerIndex:sizeof(int)];
SCNGeometry *geo = [SCNGeometry geometryWithSources:@[src] elements:@[ele]];

scj643

I actually need people to help make an API for scenekit so we can do this type of stuff with a python AI

cvp

I would like to help but I think I know not enough objective c for that...
When I program in objc, I spend hours before it works.

scj643

https://github.com/scj643/objc_tools is my repo

cvp

I know your repo, often checked...

momorprods

hey, digging out this old topic - did you have chance into the triangle mesh generation?

I have started converting the Obj-c snippet above, but it crashes Pythonista at the geometrySourceWithVertices call. Probably my bad, but I’m clueless about how to fiw this:

verts=[SCNVector3(0, 0, 0), SCNVector3(1, 0, 0), SCNVector3(0, 1, 0)]

src = SCNGeometrySource.geometrySourceWithVertices_count_(POINTER(verts),3)

cvp

@momorprods No, sorry, I didn't success...

JonB

It wouldn't be POINTER here. Try byref.

JonB

Actually, verts must be a ctypes array, not a python list.

momorprods

oh ok thanks, going to try that and keep you posted!

momorprods

Made this, but still crashing. Am I making another noob mistake?

verts=[0.0,0.0,0.0 , 1.0,0.0,0.0 , 0.0,1.0,0.0]
arr = (ctypes.c_float * len(verts))(*verts)
src = SCNGeometrySource.geometrySourceWithVertices_count_(byref(arr),3)

cvp

@momorprods Perhaps this (at least, no crash 😀)

class SCNVector3(Structure):
	_fields_ = [('x', c_double), ('y', c_double), ('z', c_double)]

And

    verts=[SCNVector3(0, 0, 0), SCNVector3(1, 0, 0), SCNVector3(0, 1, 0)]
    verts_array = (SCNVector3 * len(verts))(*verts)
    SCNGeometrySource = ObjCClass('SCNGeometrySource').geometrySourceWithVertices_count_(
    verts_array,len(verts),
    restype=c_void_p,
    argtypes=[POINTER(SCNVector3), c_ulong],)

momorprods

wooohoooo thanks!!

momorprods

Making some good progress thanks to your help. But I’m getting a last crash on the very last instruction - any idea?

#triangle generation
verts=[SCNVector3(0, 0, 0), SCNVector3(1, 0, 0), SCNVector3(0, 1, 0)]
verts_array = (SCNVector3 * len(verts))(*verts)

src = ObjCClass('SCNGeometrySource').geometrySourceWithVertices_count_(
    verts_array,len(verts),
    restype=c_void_p,
    argtypes=[POINTER(SCNVector3), c_ulong],)
    
indexes=[0,1,2]
indexes_array = (c_ulong*len(indexes))(*indexes)
datIndexes = ObjCClass('NSData').dataWithBytes_length_(indexes_array,len(indexes_array))
 
ele=ObjCClass('SCNGeometryElement').geometryElementWithData_primitiveType_primitiveCount_bytesPerIndex_(datIndexes,SCNGeometryPrimitiveTypeTriangles,1,4)
   
# CRASH Here: 
geo = ObjCClass('SCNGeometry').geometryWithSources_elements_(src,ele)

cvp

@momorprods I've read that indices must contain a first element with the number of points but I don't know if it is true.
sources and elements must be arrays
But I have also a crash with my code
See faultlog below but I can't solve the problem, sorry

    verts = [SCNVector3(0, 0, 0), SCNVector3(1, 0, 0), SCNVector3(0, 1, 0)]
    verts_array = (SCNVector3 * len(verts))(*verts)
    SCNGeometrySource = ObjCClass('SCNGeometrySource').geometrySourceWithVertices_count_(
    verts_array,len(verts),
    restype=c_void_p,
    argtypes=[POINTER(SCNVector3), c_ulong],)
    sources = NSArray([SCNGeometrySource])
    
    indices = [3,0,1,2]	# number points and their indices
    indices_data = ns(indices)
    # primitiveType = 0 for triangle
    # primitiveCount = 1
    SCNGeometryElement = ObjCClass('SCNGeometryElement').geometryElementWithData_primitiveType_primitiveCount_bytesPerIndex_(indices_data,0,1,4)
    elements = NSArray([SCNGeometryElement])
    
    geometry = ObjCClass('SCNGeometry').geometryWithSources_elements_(sources, elements)

Fatal Python error: Aborted

Current thread 0x0000000100d62b80 (most recent call first):
File "/var/containers/Bundle/Application/E4751F4F-64A4-4BE6-AB9D-9C9564715002/Pythonista3.app/Frameworks/Py3Kit.framework/pylib/site-packages/objc_util.py", line 773 in call
File "/private/var/mobile/Containers/Shared/AppGroup/668A7D98-7216-47ED-917D-AA0B6173167E/Pythonista3/Documents/test6.py", line 51 in demo
File "/var/containers/Bundle/Application/E4751F4F-64A4-4BE6-AB9D-9C9564715002/Pythonista3.app/Frameworks/Py3Kit.framework/pylib/site-packages/objc_util.py", line 1066 in OMMainThreadDispatcher_invoke_imp

Thread 0x000000016fa5f000 (most recent call first):
File "/var/containers/Bundle/Application/E4751F4F-64A4-4BE6-AB9D-9C9564715002/Pythonista3.app/Frameworks/Py3Kit.framework/pylib/site-packages/objc_util.py", line 898 in call
File "/var/containers/Bundle/Application/E4751F4F-64A4-4BE6-AB9D-9C9564715002/Pythonista3.app/Frameworks/Py3Kit.framework/pylib/site-packages/objc_util.py", line 1095 in new_func
File "/private/var/mobile/Containers/Shared/AppGroup/668A7D98-7216-47ED-917D-AA0B6173167E/Pythonista3/Documents/test6.py", line 76 in <module>

Objective-C exception details:

NSInvalidArgumentException: -[SCNGeometrySource count]: unrecognized selector sent to instance 0x283276100

JonB

this works

from ctypes import *
from objc_util import *

class SCNVector3(Structure):
    _fields_ = [('x', c_double), ('y', c_double), ('z', c_double)]

verts=[SCNVector3(0, 0, 0), SCNVector3(1, 0, 0), SCNVector3(0, 1, 0)]

SCNVector3Array3=SCNVector3 * len(verts)
verts_array=SCNVector3Array3(*verts)
SCNGeometrySource = ObjCClass('SCNGeometrySource')

s=SCNGeometrySource.geometrySourceWithVertices_count_(byref(verts_array),len(verts),restype=c_void_p,argtypes=[POINTER(SCNVector3Array3), c_ulong],)

cvp

@JonB Yes, but in my code,,the crash was in

    geometry = ObjCClass('SCNGeometry').geometryWithSources_elements_(sources, elements)

cvp

@momorprods @JonB No crash with

    verts = [SCNVector3(0, 0, 0), SCNVector3(1, 0, 0), SCNVector3(0, 1, 0)]     
    SCNVector3Array3=SCNVector3 * len(verts)
    verts_array=SCNVector3Array3(*verts)
    SCNGeometrySource = ObjCClass('SCNGeometrySource')
    s = SCNGeometrySource.geometrySourceWithVertices_count_(byref(verts_array),len(verts),restype=c_void_p,argtypes=[POINTER(SCNVector3Array3), c_ulong],)
   
    indexes=[0,1,2]
    indexes_array = (c_ulong*len(indexes))(*indexes)
    datIndexes = ObjCClass('NSData').dataWithBytes_length_(indexes_array,len(indexes_array))
    # primitiveType = 0 for triangle
    # primitiveCount = 1  
    e = ObjCClass('SCNGeometryElement').geometryElementWithData_primitiveType_primitiveCount_bytesPerIndex_(datIndexes,0,1,4)
    
    geometry = ObjCClass('SCNGeometry').geometryWithSources_elements_([s],[e])
	```

Edit: but nothing visible