test: Update tests that now fail

The normals have been fixed in the shader, hence the difference
Also the sample distance is not computed in index space anymore
This explains some differences

Author: bruyeret

Sources/Rendering/Core/VolumeMapper/test/testColorMix.js

@@ -142,7 +142,7 @@ test('Test Volume Rendering: custom shader code', async (t) => {
           if (opacity1 > 0.5) {
             return vec4(0.0, 1.0, 1.0, 0.1);
           } else {
-            vec3 posIS = VCtoIS(posVC);
+            vec3 posIS = posVCtoIS(posVC);
             mat4 normalMat = computeMat4Normal(posIS, tValue);
             float opacity0 = getOpacityFromTexture(tValue[0], 0, volume.transferFunctionsSampleHeight[0]);
             vec3 color0 = getColorFromTexture(tValue[0], 0, volume.transferFunctionsSampleHeight[0]);