Path Tracing: transparency coefficient dependent on texture color

let me briefly describe my scenario:

- OCCT 7.4.0
- I have path tracing turned on:
Graphic3d_RenderingParams& aParams = myActiveView->ChangeRenderingParams();
aParams.Method = Graphic3d_RM_RAYTRACING;
aParams.IsGlobalIlluminationEnabled = Standard_True;
- I have light source: V3d_PositionalLight
- I have a texture (precisely: multiple textures) which is assigned to a plane. Each texture has stripes or patterns on it: black, white or different gray values.

Having this defined I want the transparency value of the plane to be defined by the color of 'pixel' on the texture. Example: black color - 0% transparency, white - 100% transparency, gray would be then between 0 and 100%. In other words, the plane would have various transparency values depending on the underlying texture.

Can this task be accomplished with OCCT? Any ideas or maybe even examples how to do it?