I'm trying to add something resembling ambient lighting to a photoview 360 render. I want to render an interior space of my model with a flat, shadowless lighting applied to all surfaces, as if the air itself is emitting light, in addition to the other lights in the model.

I've tried using the Primary Photoview 360 lighting for this, but I can't find any way to disable shadows for it, so that's out. I've tried using a point light with a radius larger than the model, but it still seems to concentrate the light at the center rather than illuminating evenly throught the volume of the light. I've tried using 6 directional lights at right angle to each other with shadows disabled, which almost achieves the desired effect, except that they also show up as huge balls of bright light on reflective surfaces in the model. I can't just apply self-illumination to all the materials, because the light has to be a specific color and there are multiple very different colors in the model.

Is there any way to achieve what I want?