Why an HDR lighting solution would give JAGGy shadows?

The only one difference between one render and the other is that num 1, is using an HDR file called “013-weg-naast-wei.hdr.001”, 156 Mb and its nodes setup is simpler. While num 2 is using the new HDR addon from BlenderGuru called Pro-Lighting: Skies. Its nodes setup is more complex, which I’m not including here as I’m not sure whether I’d need authorization from Mr Price. The addon is about 30 Mb, so I thought it would lighter to use. The render does take less time. I like the resulting lighting better, except it produces those ugly jaggy shadows. Any idea how to fix this?



Thanks guys,


Looks like a terminator artefact, which is caused by low poly geometry in conjunction with high contrast lighting. Try adding a Subsurf modifier to those doughnuts in order to increase their mesh density.

Thanks for replying Ikari.
So, if low poly geometry is the reason, then why isn’t “the same model” showing as jaggy with num 2 ?


Did adding a Subsurf modifier solve the issue or not?

Other than that I’m not sure if I get what you try to say. Your image #2 shows a dougnut with jaggies at the terminator line (= the transition from light to shadow on the surface). Where do we see “the same model” without artefacts at the terminator in image #2?

Or did you mean why isn’t “the same model” showing as jaggy with num 1? As I said, high contrast lighting conditions are more likely to trigger terminator artefacts than diffuse ones. And the light in #1 is so diffuse, that it’s hard to tell where the light is even coming from.

Oh, I see! Thanks for explaining.
Well, to answer your question,

576 faces not counting the Subs mod at 2 - Correction: 576 faces IS AFTER the mod has been applied.

At the moment I’m trying lower values both for Sky and Sun in the Pro Lighting: Skies addon…

You were right! :slight_smile:

The above render was done with the same addon, same models, just much lower light!

Then, my question is: If I were to go back to higher light values, BUT I were to use a normal map from a considerably higher mesh, would the jaggyness be away still? Or do I need the actual high mesh present?

Oh, never mind my question.
I just checked the normal map that model is using, it was done with a high poly mesh with nearly 600,000 faces! :frowning:
So obviously the normal map is not enough. It sucks that it seems the only solution is to bump up the number of faces in the mesh. Is this right?

Try illuminating the diffuse using a blurred version of the HDRI, possibly slightly clamped. Most of the free HDRI’s tend to give nicer terminators because they are clamped (sun not remotely bright enough). The “full HDRI’s” (I don’t know how the addon works, I do stuff my own way) I’m guessing will have a sun with truer light values, which will affect the terminator. Can’t remember which one, but one of these renderman tutorials explains this (applies to path tracers, apparently, but I’m not an expert). If all fails, try illuminating with a sun light, and faking it instead.

Thanks for your input Carl :slight_smile: