This function should be preceded by the function CalculateInstances(), the only allowed other API functions in between are UpdateVertexBuffer() and UpdateIndexBuffer().
It is expected to be called with a buffer vertexBuffer of at least the size as given by CalculateInstances().
If not called for the first time it will expect to contain the same content as from previous call, even is size is changed. This can be overruled by the function ClearedExternalBuffers().


//   Visual Studio for Windows
__int64 __declspec(dllexport) __stdcall UpdateInstanceTransformationBuffer(
            __int64             owlInstance,
            void                * transformationBuffer

//   Linux, OS-X and non-Visual Studio Windows solutions
int64_t UpdateInstanceTransformationBuffer(
            int64_t             owlInstance,
            void                * transformationBuffer

Property owlInstance

Size: 64 bit / 8 byte (value)
The handle to the specific instance in the design tree. The instance handle is static within one open model but is most probably different when the same instance is opened in another model. The instance is always exactly of one unique class.

Property transformationBuffer

Size: 32 bit / 4 byte (reference)
The calculated size that is required for the transformation buffer. This only returns a value if it has a non-zero input value.