The YF-19: Specular Maps

Learning new things every day!

So this week I’ve spent way too much time rendering tests, but I can’t help myself! The renders are looking better and better! Plus I’ve been realizing that the specular map needs its own logic, and I didn’t understand it till after rendering all these:

October 4 - specular test with strong light

October 4 – specular test with strong light

Originally I thought a specular map would just let the program know which textures would be “shinier”, which in my brain translated as brighter parts. So it made sense to make the panel lines black, the fuselage a clear gray and the brightest parts of the material, those ones that would be basically chrome, pure white. I spent many hours tweaking, adding layers upon layers of black and white parts. Then I added differences in gray to the panels, because panels are not all equal, and some things get added later to the plane during maintenance, so they would be “newer”, that means, shinier. Some other parts are old and dull and full of gross stuff, so they would be less shiny, darker.

October 5 - Texturing with a base gray all the interior mechanical parts

October 5 – Texturing with a base gray all the interior mechanical parts

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October 6 - Making specular variations on the cockpit. It looked too subtle because I was still using a strong light

October 6 – Making specular variations on the cockpit. It looked too subtle because I was still using a strong light

With the lower light you can see the variations in specularity

With the lower light you can see the variations in specularity

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But I wasn’t counting on this: Reflective materials like metal can reflect darker colours from the background too. So if something has a high reflectiveness (specular value closer to white) it will reflect more of the background than something non reflective (matte). That means it’s not necessarily going to be shinier by being more reflective. Sometimes it looks the other way around, which is what I concluded when I started making these renders.

With variations in specularity and the dirt layer in the same specularity map

With variations in specularity and the dirt layer in the same specularity map…

... when switching the colour with a single gray texture, the problem is visible

… when switching the colour with a single gray texture, the problem is visible

The specular map had the layer I had made for the diffuse map with the dirt and dark stuff I’ve been layering around. My logic was that dirt wouldn’t reflect that much light as a clean surface, so putting this would make the material even more realistic. That makes sense on the surface, but it doesn’t make sense if you’re putting a light that reflects a darker background than the light material of my fuselage. If it’s too much of a difference, the result is a weird inverted feel, like shadows looking lighter than lighted surfaces.

October 7 - Testing the specularity issue with a base gray colour

October 7 – Testing the specularity issue with a base gray colour

Test with very low lights of the specular map

Test with very low lights of the specular map

Problem visible on the wing aleirons: The dark oil spills look clearer because they are not reflecting the dark bg like the rest of the metal

Problem visible on the wing aleirons: The dark oil spills look clearer because they are not reflecting the dark bg like the rest of the metal

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October 8 - Test of very dark shadows with specular map

October 8 – Test of very dark shadows with specular map

The conclusion of these experiments is that panels should have a difference in specularity, but not a huge one, and if I’m adding dirt to the specular values, the difference in brightness should be very very subtle. I’m in the process of tweaking these things to make a few final renders, and then on to my most favourite part of making these textures!! The thing I’ve been eagerly awaiting for: labels and signs.

October 9 - Specular map with no dirt in it, mid lighting

October 9 – Specular map with no dirt in it, mid lighting

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About Eduardo

I'm some dude with a huge love for animation and film. I've been working in TV animation for the past 6 years in New Zealand. I love dragons, pointy metal things that can cut dragons, and flight simulators.
This entry was posted in Blender Modelling, The YF-19 Project and tagged , , , , , , , , , , , , . Bookmark the permalink.

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