Hello! Help for texture/modelling/lighting bugs

Technical Support Modeling
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1

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Hi! Probably a silly question but why does this happen and is there an easier way to fix this?

Edit : I forgot to explain the problem. The problem is the weird shadow artifact around the curve of stone lantern here. Left is the wireframe of the mesh while right is the mesh with an applied Shade Smooth

I’ve been working on this entire environment project for almost a year now (half of it was procrastinating sadly tbh) but I want to complete this and started running into issues like this.

Its one thing if its a small object that’s not that visible in the camera angle but this stony guy is decently big and I decided to bite the anxiety to ask.

2

I guess you mean the black “borders”.. do you have black as “background color” in your texture and your UV’s are “exactly on the spot” ?

3

What issue are you talking about, it would be useful if you could send an annotated screenshot circling or highlighting the issue.

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Ah sorry. I shouldve explained more. Its these weird shadow artifacts formed when light interacts with the mesh

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Im not sure what you mean by the black borders but its definitely these weird shadow artifacts formed when the hdri interacts with the mesh

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6

OK that makes sense, could that potentially be a shadow cast from your lighting, if you move the light or add a second one, that should help you know.

7

Hmmm i suppose but im kinda already targetting the angle of the main light source for the shadow direction. Now, strangely, if i add subdivision modifier, the shadow looks nicer but now im wondering what the heck is forming that shadow to begin with.

Below is a screenshot after i moved the object away from its position and yet that shadow is still there. Does it mean its a uv issue?

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8

Looks like a normals issue

Edit mode → Select all → Recalculate normals (Shift + N)

9

Hi! Thanks for pitching in. I tried recalculating the outside normals (and inside for testing) but no difference sadly.

10

Hmm got any overlapping geometry there? Like an extra edge that accidentaly isn’t connected or something like that?

11

I did as you suggested and it didnt work but i think i figured it out. Maybe. Sort off?

For starters, i tried modelling a new one beside it and thought it was strange that it forms the same shadow. Just no shade smooth.

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But then i tried changing the hdri. Specifically to a blender Sky texture and suddenly, there you have it, no weird shadow artifact.

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So i guess it was a hdri issue? Granted it doesnt exactly explain why it looks like that specifically because i tried adding another cube beside it and well, below shows it doesnt have that weird shadow. Only forming if i specifically model the mesh this curved way.

Disclaimer, i turned off the hdri’s transparency

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So i guess its a hdri issue which is really unfortunate because i kinda liked everything else it interacts with.

Sorry for this weird headache of an issue lol

12

Ohh.. i thought you was talking about the “black lines” .. :sweat_smile:

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..well your roof is not really “curved” but more “stepped” so the shadows are also not “smooth”.. as you subdiv example does show..

The more subdivs the nore curvation and smooth shadows..

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13

Would it be possible for you to share your Blender file so that I can take a look. What @Okidoki said is correct, increasing the subdivide is going to make it more curved, therefore providing more smooth shadows.

14

I think this is the same problem as this thread;

Smooth shade does have some problems with low poly shadows, subdividing the mesh solves it because there is more geo (that smooths out the form) to work with.

If you are using simple smooth shade try using “shade auto smooth” instead it often works better.

15

Yeah, this seems like a shadow terminator problem. :thinking:

16

Unfortunately it says new users cant share attachments. Nevertheless, thank you everyone @Withers99 @DNorman and Okidoki (sorry, new user limit again)

I think I’m sure that the shadow was made by the HDRI (its not clear skies so likely the culprit) and i guess I have to bite and make mesh higher poly.

Thank you again for pitching in. Hopefully I get to finish this damn project of mine