Effectively Lighting Metallic Artifacts

culturalheritage
lights
photogrammetry

(Oakeshott) #1

Hi all!

I was wondering if anyone had advice for where to start with choosing background lighting and applying individual light sources to objects, especially metallic ones. I’ve done a fair bit of experimentation in Sketchfab, but my knowledge on 3d modelling is fairly limited, and any success I’ve had has been purely through trial and error. I can get some models to look fairly decent (imo), but others are more questionable, and I don’t have a consistent approach for how to tackle the lighting from piece to piece.

For example, here’s the most recent piece we released from the collection. I think this one looks fairly good, and think the lighting effectively captures the “feel” of the piece.

By comparison, here is the piece I am currently working on. It just feels like regardless of what I do with the lighting, one part ends up washed out, or another gets lost against the background.

An image of the hilt for reference.

I would love to hear any thoughts people might have.

Thanks in advance,

Dale


(Nebulousflynn) #2

Hi @oakeshott - first off, congratulations on your great scans of these swords, tbh I think oboth examples look pretty great! A couple of suggestions…

To make your life easier you could switch to a plain background, either a solid colour or by simply turning down the brightness of the bg in the general tab (this won’t affect the PBR lighting).

To define the shape of the hilt (for example on a dark background) you could use one of your directional lights as key light (example) set to 50+, pure white.


(Oakeshott) #3

@nebulousflynn Thanks for the advice! I switched back to the background we have used for some of our other pieces, though I may try just a solid black or more neutral grey as well. I messed around more with the lighting on the Schloss Erbach sword, as well as added a touch of bloom to highlight the really reflective parts of the blade. I’m tempted to go back and lighten up the leather texture on the grip just a touch in photoshop to see if it would help without compromising the realistic feel of the piece.

Would you recommend that the lights be attached to the camera? That is what I have been doing, so we can see the back of the piece as well, but I am not sure if this is the best practice.

I also have one other piece that has been a total pain just because of its extremely dark patina, so I may post that here too and see if anyone has any advice.


(Nebulousflynn) #4

It’s easy to get lost in endless tweaking of 3D Settings (I’ve been there many times), but really I think the swords (and other models you have posted) look great! It can be useful to switch back to shadeless mode once in a while for a quick reality check too :slight_smile:

In general lights attached to the camera reduce viewer performance (but they do lend a nice moving shine, especially on metallic or shiny surfaces). You can still use non-attached lights to illuminate certain views/angles, and I’d recommend using one light attached to the camera at most.

Another trick (if you are finding some details getting lost in darker areas) is to use the base colour texture on the emission channel, set very low to 1 or 2.


(Oakeshott) #5

@nebulousflynn Suddenly problems! I will put in a support request as well, but I figured you might know something, and I was already talking to you about this model. For some reason, suddenly the Schloss Erbach sword does not want to render properly. It looks fine when I am editing the properties of the model, but when viewing it outside of the editor the model appears flat and dark. It feels like the metalness and roughness channels are not rendering, and perhaps the light sources are having issues too.

I only ask because I wanted to release that model to the public and to my patrons this week, but I would prefer it be rendering properly before I do. Thanks!


(Oakeshott) #6

Never mind. I tried changing the model off of PBR, and then back, and now it is rendering properly. Good to know I am (sometimes) self sufficient.