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When instanciating more than 32 textured vtkFollower, some errors are logged about too many textures being send to the GPU and final render is totally broken.

Replacing vtkFollower by vtkActor gives no errors and works fine even with 100+ textures.

Errors :

2021-10-18 16:55:26.100 (   1.300s) [        EA38C780]     vtkOpenGLState.cxx:1795  WARN| Hardware does not support the number of textures defined.
2021-10-18 16:55:26.100 (   1.300s) [        EA38C780]vtkOpenGLPolyDataMapper:2648   ERR| vtkCompositeMapperHelper2 (0x55b142535840): failed after Render 1 OpenGL errors detected
  0 : (1281) Invalid value

Program to reproduce :

#include <vtkCell.h>
#include <vtkIdList.h>
#include <vtkNew.h>
#include <vtkRTAnalyticSource.h>
#include <vtkStaticCellLocator.h>
#include <vtkPlaneSource.h>
#include <vtkActor.h>
#include <vtkFollower.h>
#include <vtkRenderer.h>
#include <vtkCompositePolyDataMapper.h>
#include <vtkCompositePolyDataMapper2.h>
#include <vtkRenderWindow.h>
#include <vtkNew.h>
#include <vtkJPEGReader.h>
#include <vtkRenderWindowInteractor.h>
#include <vtkTexture.h>

#include <vector>

//////////////////////////
constexpr int LOOP = 6;
const std::vector<const char*> TEXTURES = {
  // list of texture name ...
};
//////////////////////////

int main(int, char *[])
{
  vtkNew<vtkRenderer> renderer;
  const std::string prefix = "/home/timothee/Data/materials/textures/";

  for (int i = 0; i < LOOP; ++i)
  {
    for(int j = 0; j < LOOP; ++j)
    {
      vtkNew<vtkPlaneSource> source;
      source->SetCenter(i, j, 0);
      source->Update();

      const std::string filename = prefix + TEXTURES[(i + LOOP *j) % TEXTURES.size()];
      vtkNew<vtkJPEGReader> reader;
      reader->SetFileName(filename.c_str());
      vtkNew<vtkTexture> texture;
      texture->SetInputConnection(reader->GetOutputPort());

      vtkNew<vtkCompositePolyDataMapper2> mapper;
      mapper->SetInputConnection(source->GetOutputPort());

      vtkNew<vtkFollower> actor;
      actor->SetCamera(renderer->GetActiveCamera());
      actor->SetMapper(mapper);
      actor->SetTexture(texture);

      renderer->AddActor(actor);
    }
  }

  renderer->ResetCamera(-1, LOOP + 1, -1, LOOP + 1, -1, 1);

  vtkNew<vtkRenderWindow> window;
  window->AddRenderer(renderer);
  window->SetWindowName("Follower test");

  vtkNew<vtkRenderWindowInteractor> interactor;
  interactor->SetRenderWindow(window);

  window->Render();
  interactor->Start();

  return 0;
}