Basic lighting question

This should be obvious but why is it that when the checkbox in this filter is ticked there is not a reflection of the environment? In other words, why doesn't a constant height reflect?

RefQ.ffxml

lol, it's white.

huh? i only know when i'm here and flipping around the forums. the little icon is blue when there's a new post.

a constant white or constant anything has zero surfaces, or rather one surface, so how could you see any differences between surface and reflection?

Quote
Kraellin wrote: a constant white or constant anything has zero surfaces

A wall mirror has a single surface

I'm just not getting it, sorry. I can see the room in a flat mirror.

Okay, then what about this one:

RefQ2.ffxml

well, you're still only mapping the height with a profile gradient. and there's still no difference in the all white field. you didnt change the all white field in image. add a surface and you'll see what i mean.

RefQ2 rev 1.ffxml

in fact, it looks like it's very much not linear. notice how the profile gradient has remapped the sphere. if it were linear through the height, you'd have dark on the one side going to light on the other. but height is apparently mapping it to highs and lows like elevation gradient does.

This may be the flattest possible mirror.

RefQ2 rev3.ffxml

ok, in refq2 rev2, unplug your circular arc and plug the profile grad into the surface and you shld see what's going on. remember, you've also got a lighting environment affecting all this and not just height.

Okay, I can't hang - too much reflection for one day. Hopefully it will all be clear tomorrow.

You're right about the simplicity I will start there in the morning. Have a good one.

It is obvious that when the height is set to a constant or graded with a linear profile the surface is still reflecting – this can be verified by moving the brightness and saturation sliders under lighting. However, there are no details from the scene visible in the reflections. This may be due to a distance issue, like pressing a mirror right up to your face – even touching the eyeball. Anyway it doesn't matter because I have found a way to get the effect I wanted for my tiles project by introducing a multiply blend mode to linear gradients as can be seen in the attached snippet.
No doubt that there is a lot more to it but since I can now get it to do what I want it to I don't care about it any longer.

Thanks so much for the help Kraellin.

RefQx1.ffxml

Okay onyXMaster, that explanation is fine. Thank you.

Kraellin did you notice that last snippet? I never would have guessed that the reflection map for a flat mirror would look like that - it's no wonder I found it confusing.

RefQx1 m2k.ffxml