Author Topic: Two almost identical objects, one material - two results  (Read 687 times)

2018-05-24, 20:23:18


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I have two poly objects (walls) in my scene which have the same material applied. I have a UVW map on both of them with the map channel the same as the material's/maps. When I render the scene the light shadow breaks differently on these two objects. Please see the attached images. I created the first object earlier today, made the material and just now created the second object and applied the same material.

I have the RGB Level set to 0.3 in the Normal bump map of my material which creates a soft shadow on my first object. If I set it to 1.0 the shadow becomes sharp just like in the second object.
However with the exactly same material applied, the second object always has a hard shadow projected on to it even with the RGB Level set to 0.3.

I cant' figure out what is going on here, the object themselves have the same Object properties and are placed on the same position.

There is also another problem with the second object. The top right area where the light hits it is always overexposed even if I bring the RGB Level of the Diffuse map to 0.5 (third picture). With the same material applied on my second and newly made objects (walls) the reflections on my main object (car) become overexposed. It really messes it up. I am using Corona Sun.

1.jpg - first object
2.jpg - second object
3.jpg - second object overexposed (Diffuse RGB 0.5)

Thanks for the help.
« Last Edit: 2018-05-24, 20:35:08 by ynotsop »

2018-05-24, 21:13:37
Reply #1


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Hi. Hard to tell without the actual scene, but here are two things to try:

1) Looks like your wall are planes. If that's so, then try giving them thickness (shell modifier) or use boxes instead.

2) If your normal map is made correct, you shouldn't adjust the RGB level on them. Use the amount value instead (ideally it should be 1).

Hope it helps

2018-05-24, 21:34:45
Reply #2


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If your materials have been setup with PBR in mind, then you shouldn't change the material parameters to compensate for lighting.Either your lighting is too bright, or you simply need to stop down the whole image in post (reduce exposure).

Remember, if you photograph a bright wall in sunlight next to a shadow, you need to choose what part of the image you are exposing for. Either your bright parts will blow out, or your shadows will be dark. Well, that is if you are aiming for realism. If not, then break the rules and have both areas exposed 'to the eye' and mess with the materials all you want.