Fix scalar bar display for different visualization modes (#8)

# Fix scalar bar display and add image hash validation for 3D plots

Introduce `check_image_hash` utility for ensuring image consistency in 3D plot tests. Updated tests to validate rendered images using predefined hashes, added dependencies (`imagehash`, `pillow`), and refined plotting logic for structured grids.

The PR makes the following changes:
- Fixed scalar bar display logic to show appropriate bars based on the active scalar field
- Modified structured grid plotting to handle lithology and scalar fields differently
- Simplified `_plot_in_matplotlib` function by removing unused parameter
- Added image hash validation to ensure visual consistency in tests
- Updated all 3D plot tests to verify output against predefined image hashes

Author: Leguark

gempy_viewer/API/_plot_3d_API.py

@@ -180,6 +180,7 @@ def plot_3d(
         )
 
     if data_to_show.show_scalar[0] is True:
+        # TODO: Make sure that when we are ere we do not change the scalar_bar
         plot_structured_grid(
             gempy_vista=gempy_vista,
             vtk_formated_regular_mesh=vtk_formated_regular_mesh,
@@ -190,8 +191,7 @@ def plot_3d(
             cmap='magma',
             **kwargs_plot_structured_grid
         )
-
-    if True:
+    else: # * If it is not a scalar field, we use the structural frame bar
         set_scalar_bar(
             gempy_vista=gempy_vista,
             elements_names=structural_frame.elements_names,
@@ -207,15 +207,15 @@ def plot_3d(
         gempy_vista.p.show(screenshot=fig_path)
 
     if image is True:
-        show = _plot_in_matplotlib(gempy_vista, show)
+        show = _plot_in_matplotlib(gempy_vista)
 
     if show is True:
         gempy_vista.p.show()
 
     return gempy_vista
 
 
-def _plot_in_matplotlib(gempy_vista, show):
+def _plot_in_matplotlib(gempy_vista):
     gempy_vista.p.show(screenshot=True)
     img = gempy_vista.p.last_image
     plt.imshow(img)

gempy_viewer/modules/plot_3d/drawer_structured_grid_3d.py

@@ -45,35 +45,25 @@ def plot_structured_grid(
             crinkle=False,
             invert=True
         )
-
-    add_regular_grid_mesh(
-        gempy_vista=gempy_vista,
-        structured_grid=structured_grid,
-        cmap=cmap,
-        opacity=opacity,  # BUG pass this as an argument
-        **kwargs
-    )
-
-
-def add_regular_grid_mesh(
-        gempy_vista: GemPyToVista,
-        structured_grid: "pv.StructuredGrid",
-        cmap: Union[mcolors.Colormap or str],
-        opacity: float,
-        **kwargs
-):
-    if isinstance(cmap, mcolors.Colormap):
-        _clim = (0, cmap.N)
+        
+    if active_scalar_field == 'lith':
+        gempy_vista.regular_grid_actor = gempy_vista.p.add_mesh(
+            mesh=structured_grid,
+            show_scalar_bar=False,
+            interpolate_before_map=True,
+            opacity=opacity,
+            **kwargs
+        )
     else:
-        _clim = None
-    gempy_vista.regular_grid_actor = gempy_vista.p.add_mesh(
-        mesh=structured_grid,
-        # ? scalars=main_scalar, if we prepare the structured grid do we need this arg?
-        show_scalar_bar=False,
-        interpolate_before_map=True,
-        opacity=opacity,
-        **kwargs
-    )
+        gempy_vista.regular_grid_actor = gempy_vista.p.add_mesh(
+            mesh=structured_grid,
+            cmap=cmap,
+            show_scalar_bar=True,
+            interpolate_before_map=True,
+            opacity=opacity,
+            **kwargs
+        )
+    
 
 
 def _mask_topography(structured_grid: "pv.StructuredGrid", topography: Topography) -> "pv.StructuredGrid":

requirements/dev-requirements.txt

@@ -1,6 +1,9 @@
 -r optional_requirements.txt
 
 pytest
+gempy
+imagehash
+pillow
 pydantic
 gempy_engine>=2025.2.0dev0,<2025.3.0
 gempy>=2025.2.0dev0,<2025.3.0

tests/test_plotting/test_plot_3d.py

@@ -5,6 +5,7 @@
 import gempy as gp
 from gempy.core.data import GeoModel
 from gempy_viewer.core.scalar_data_type import TopographyDataType
+from tests.util_tests import check_image_hash
 from tests.conftest import _one_fault_model_generator
 
 np.random.seed(1234)
@@ -19,10 +20,11 @@ class TestPlot3DSolutions:
     def test_plot_3d_solutions_default(self, one_fault_model_topo_solution):
         print(one_fault_model_topo_solution.structural_frame)
         gpv.plot_3d(one_fault_model_topo_solution, image=True)
+        
 
     def test_plot_3d_solutions(self, one_fault_model_topo_solution):
         print(one_fault_model_topo_solution.structural_frame)
-        gpv.plot_3d(
+        plot3d = gpv.plot_3d(
             model=one_fault_model_topo_solution,
             show_topography=True,
             show_scalar=False,
@@ -32,9 +34,14 @@ def test_plot_3d_solutions(self, one_fault_model_topo_solution):
             image=True
         )
 
+        check_image_hash(
+            plot3d=plot3d,
+            hash='07040030001'
+        )
+
     def test_plot_3d_solutions_volume_and_input(self, one_fault_model_topo_solution):
         print(one_fault_model_topo_solution.structural_frame)
-        gpv.plot_3d(
+        plot3d = gpv.plot_3d(
             model=one_fault_model_topo_solution,
             show_topography=False,
             show_scalar=False,
@@ -45,9 +52,15 @@ def test_plot_3d_solutions_volume_and_input(self, one_fault_model_topo_solution)
             kwargs_plot_structured_grid = {'opacity': 0.5}
         )
 
+
+        check_image_hash(
+            plot3d=plot3d,
+            hash='07400018000'
+        )
+
     def test_plot_3d_solutions_only_volume(self, one_fault_model_topo_solution):
         print(one_fault_model_topo_solution.structural_frame)
-        gpv.plot_3d(
+        plot3d =gpv.plot_3d(
             model=one_fault_model_topo_solution,
             show_topography=False,
             show_scalar=False,
@@ -57,9 +70,14 @@ def test_plot_3d_solutions_only_volume(self, one_fault_model_topo_solution):
             image=True
         )
 
+        check_image_hash(
+            plot3d=plot3d,
+            hash='07c00000000'
+        )
+
     def test_plot_3d_solutions_only_input(self, one_fault_model_topo_solution):
         print(one_fault_model_topo_solution.structural_frame)
-        gpv.plot_3d(
+        plot3d =gpv.plot_3d(
             model=one_fault_model_topo_solution,
             show_topography=False,
             show_scalar=False,
@@ -69,32 +87,53 @@ def test_plot_3d_solutions_only_input(self, one_fault_model_topo_solution):
             image=True
         )
 
+        check_image_hash(
+            plot3d=plot3d,
+            hash='06000038040'
+        )
+
     def test_plot_3d_scalar_field(self, one_fault_model_topo_solution):
-        gpv.plot_3d(
+        plot3d = gpv.plot_3d(
             model=one_fault_model_topo_solution,
             active_scalar_field="sf_1",
             show_scalar=True,
             show_lith=False,
+            show_topography=False,
             image=True
         )
 
+        check_image_hash(
+            plot3d=plot3d,
+            hash='07600210000'
+        )
+
     def test_plot_3d_solutions_topography(self, one_fault_model_topo_solution):
-        gpv.plot_3d(
+        plot3d =gpv.plot_3d(
             model=one_fault_model_topo_solution,
             show_topography=True,
             topography_scalar_type=TopographyDataType.TOPOGRAPHY,
             image=True
         )
 
+        check_image_hash(
+            plot3d=plot3d,
+            hash='06480000000'
+        )
+
     def test_plot_3d_solutions_topography_geological_map(self, one_fault_model_topo_solution):
-        gpv.plot_3d(
+        plot3d =gpv.plot_3d(
             model=one_fault_model_topo_solution,
             show_lith=True,
             show_topography=True,
             topography_scalar_type=TopographyDataType.GEOMAP,
             image=True
         )
 
+        check_image_hash(
+            plot3d=plot3d,
+            hash='07040030001'
+        )
+
 
 class TestPlot2DSolutionsOctrees:
     @pytest.fixture(scope='class')

tests/util_tests.py

@@ -0,0 +1,9 @@
+from gempy_viewer import GemPyToVista
+
+
+def check_image_hash(plot3d: GemPyToVista, hash:str):
+    import imagehash
+    from PIL import Image
+    img = Image.fromarray(plot3d.p.last_image)
+    hash_ = str(imagehash.colorhash(img))
+    assert hash_ == hash, f"Image hash is not correct: {hash_}"