Shading white cards

…We've done enough work on our materials that we can fine tune the lighting.…Part of that process is to set up our white cards.…Remember, we created these planes and constrained them to the area lights.…And the reason for that is so we can have separate…control over the reflections and the…specular highlights coming from these lights.…Remember we discussed this in the lighting chapter.…You can make the area lights visible, but if…you do that what's going to happen is the…reflection component from the area lights is going to…override the specular component and that's not a good outcome.…

We need them both and we need them to add together.…To accomplish this, I've created a white card which will produce reflections.…And I have not enabled visibility on the area lights…and the area lights will only produce the specular highlights.…Okay, so to make this work we need highly self illuminated material…on the white cards, and so there will be a very clear demonstration.…We want to do a rendering with the lights turned off.…