From what I can tell, it looks like the "render_config_extension" setup works only for the Editor and it fails on the Test Level or the Game. The way that I got around it is going back to the original setup of changing the "renderer.render_config" file.
I am attaching my running version of it. You will need to replace (make a backup first just in case) the one in "core/stingray_renderer/" folder. If you declare a separate "renderer.package" and "renderer.render_config", the editor might start throwing errors about not being able to find a whole bunch of shaders and going out of whack.
If you are replacing the "renderer.render_config" file, remember to comment out the "render_config_extensions" portion that deals with the clouds in the "settings.ini" file.
Also, if you want to use the latest code from the git master, overwrite the "clouds.shader_source" file with the one attached and change in the ".component" files under "metadata" the "component" value from "render_data" to "data"(attached just in case).
Also forgot to mention, that you might need to change in the "clouds.lua" file the referencing of "Renderer" to "stingray.Renderer"
function Clouds:generate()
cloud_resource3 = stingray.Renderer.resource("clouds_result_texture3")
cloud_resource1 = stingray.Renderer.resource("clouds_result_texture1")
cloud_resource2 = stingray.Renderer.resource("clouds_result_texture2")
resource_maping1 = {}
resource_maping2 = {}
resource_maping3 = {}
resource_maping1["input"] = cloud_resource1
resource_maping2["input"] = cloud_resource2
resource_maping3["input"] = cloud_resource3
resource_maping1["output"] = cloud_resource1
resource_maping2["output"] = cloud_resource2
resource_maping3["output"] = cloud_resource3
stingray.Renderer.run_resource_generator("cloud_generator_texture1", resource_maping1)
stingray.Renderer.run_resource_generator("cloud_generator_texture2", resource_maping2)
stingray.Renderer.run_resource_generator("cloud_generator_texture3", resource_maping3)
end
