Surface shader default lighting

Hi,
I am writing a surface shader that renders fake lighting whenever there is shadow. I am seeing some weird behaviour when there are no lights in the scene. Basically the shader is being called with a lightDir parameter that is a semi random vector (usually along the Y axis), but it can be pretty much anything.

Any idea what could be causing this? How to disable?
I can add a directional lighting, but then the shader will have to ignore that particular light.

Thanks.

 

Someone else may be better suited to answer the question, but I'm trying to wrap my head around what you're trying to do. Am I getting this correctly that you want to light the object in the shader rather than using an external/unity light object - such as baking a lightmap? Or is there a different goal? Any pics that might be able to help clarify?

Stab in the dark - There may be additional useful info in this thread:
http://answers.unity3d.com/questions/272749/how-to-write-unlit-surface-shader.html

 

Yeah, the base pass will get given a light direction, but it will be gibberish (usually the last used light that's been passed in).

You can multiply it by the lightColour (which will always be black if there is no light).

 

Thanks for the replies.
Multiplying by the light color did remove the extra light. In the end, I ignored directional lights, since the effect I am interested in achieving only applies when using spots/point lights.

The idea is that unlit areas get sort of a shine, kinda like specular highlights caused by indirect light.

I am still working on a better way to handle things, since my solution completely removes directional lights, but I'll figure something out, thanks!