Digital Art Zone

I like your stucco shader… TUTORIAL TUTORIAL!!

holly wetcircuit - 09 December 2012 01:21 PM

I like your stucco shader… TUTORIAL TUTORIAL!!

I hate to admit it, but it’s one of the included shaders with the spot size scaled down a bit in the bump channel.

It’s under Misc. and is called Semi-gloss Interior.

I added a translucent spere around the bulb, changed the brightness to 100% and the GI to 100%, the rest is the same as before. This looks much better to me :D

-without GI
-with GI

Elele - 09 December 2012 01:49 PM

I added a translucent spere around the bulb, changed the brightness to 100% and the GI to 100%, the rest is the same as before. This looks much better to me :D

-without GI
-with GI

I’m glad you’re getting good results. I don’t know what your plans are for the final image, but if you add more lights, you’ll need to do what RoguePilot suggested in an earlier post and adjust down the light distance and adjust upward the falloff for your lights or it will wash out your image.

evilproducer - 09 December 2012 01:53 PM

Elele - 09 December 2012 01:49 PM

I added a translucent spere around the bulb, changed the brightness to 100% and the GI to 100%, the rest is the same as before. This looks much better to me :D

-without GI
-with GI

I’m glad you’re getting good results. I don’t know what your plans are for the final image, but if you add more lights, you’ll need to do what RoguePilot suggested in an earlier post and adjust down the light distance and adjust upward the falloff for your lights or it will wash out your image.

Yes, this was just a quick test render. Thanks a lot :D

Elele - 09 December 2012 10:46 AM

I had trouble finding closed room images, but they illustrate the IL nicely. Here are some other examples in closed rooms.
I like the reflected color from the surfaces, that’s exactly what i want. But I don’t want the entire room to be colored, it is a subtle effect.

To get the subtle color effect you are trying for, you can do it faking GI with colored spotlights. Put them below your floor and above your ceiling. It may require a few. Experiment with your brightness setting and range falloff and other settings as well. You could color your spotlight under your red floor the same color and position it near your wall below the floor geometry. It was a technique Sub7th showed us in his fruit bowl tute.

The first image has the spotlight enabled on all objects, the second image without the spotlight enabled

And one with 80 percent range falloff. Looks pretty much like enough bounce light to me there.

The method using additional lights does seem handy, but I haven’t used it much yet caus i don’t have the skill to get good results. Also I usually render pretty simple scenes so the HQ GI renders rarely take more than an hour, so I’m wondering if in the end faking the GI is faster.

There’s a bunch of sample interior scenes that come with Carrara. The easiest way to get to them is to use the scene wizard. There’s scenes with caustics, GI and fake GI, so you can see how the scene was put together. It helped me quite a bit. I had forgotten about it until Kevin posted his examples which were made with the sample interior set.

Elele - 09 December 2012 02:51 PM

The method using additional lights does seem handy, but I haven’t used it much yet caus i don’t have the skill to get good results. Also I usually render pretty simple scenes so the HQ GI renders rarely take more than an hour, so I’m wondering if in the end faking the GI is faster.

Depends on what you want to do. I’m no wiz at this stuff but it didn’t take long to set it up at all. I would say you’d get your results much, much faster than with GI. Also, you can figure out pretty quickly if something is working or not because it renders so fast (if you don’t have a ton of other things to slow it down).

evilproducer - 09 December 2012 03:11 PM

There’s a bunch of sample interior scenes that come with Carrara. The easiest way to get to them is to use the scene wizard. There’s scenes with caustics, GI and fake GI, so you can see how the scene was put together. It helped me quite a bit. I had forgotten about it until Kevin posted his examples which were made with the sample interior set.

Yep, I check some of those from time to time to get ideas.

Elele - 09 December 2012 09:22 AM

Do you have some example renders where you used it to fake GI (preferably in a complex scene)?
I’m kinda wondering how long it takes to set up though. Usually my GI renders don’t take too long, even on high quality settings. Sometimes the high quality renders still show errors though, so having an alternative would be usefull.

Yeah, I’ve got one I can show you using maybe 4 (or was it 5) lights to simulate GI. And I despise the term “fake GI” because it makes it sound like it’s a poor substitute. It’s not. If you understand light and materials you can do a nice job. Especially compared to those who don’t understand light and materials and set up their scenes using poor modelling and just hit the GI button and expect wonders. 

Now, again, if you want to simulate what you see in real life, you need to model your scene as you see it in real life, and simulate light as it acts in real life. I contend that you could do an excellent job of reproducing those sample images you posted if you modelled the scenes to correspond to how those lights and materials really are.

But to do that you have to understand stuff. For those who think it’s some sort of “zen”, and don’t want to get cooties from that icky science stuff, then it’s going to be a lot tougher and take a lot longer and may have poorer results. But IMO, you can’t get around it: you’ve got to understand the basics if you want to do this stuff.

And for those who think it takes a long time to simulate GI, it doesn’t. In fact, if you understand stuff, you can set up basic scenes with a few pre-set lights that you already know are gonna be needed. You KNOW for an outdoor scene you’ll have a main sunlight, you know what its colors are, you know there will be a primary bounce light off the ground, and you KNOW there will be blue skylight coming from all sides.

And for an indoor scene, you KNOW you’ll have some primary light sources, and you KNOW that there will be floor and wall bounce lights.

But you have to understand colors and diffuse and light properties and lots of icky science stuff. If you don’t, then don’t be surprised if your results don’t match your reference photos.

And in fact, I regularly recommend that a GREAT learning exercise is to take an actual photo and figure out how to model that scene to get a render that looks exactly the same as the photo. You should try it….....

And by the way, there is a huge downside to using GI or radiosity or whatever….

It’s called “artistic license”. The ability an artist has to take reality and modify it to suit his purposes, to generate a mood in an image, to tell a story, to generate a certain emotion in his viewers. GI tries to reproduce reality. Artists generally want to take that one step further. They want to twist reality a bit to enhance a mood or an emotion. With GI, you basically set up your scene, and the GI simulator figures out how light would behave in that scene.

But often you don’t want that. Often you want to exaggerate the lighting, to generate, for example, a mood of mystery, or joy, or serenity.

Now if you’re a hobbyist whose only interest is to amaze himself that he could generate an image that looks all real and stuff, and have no interest in making images to tell a story or for others to enjoy, then yeah, do whatever is fun. But if you want to have flexibility and control over your images so you can tell your story, then GI might be less than ideal.

And FWIW, this is not a new technique, or something that was discovered by anyone here. We were doing this back in the ‘80s and 90’s before radiosity was even invented, and when GI solutions took weeks to render with the slow processors we had back then. And big studios are still doing it today to save render time and to have control and flexibility.

It’s a good thing….

And here’s one from long ago using 6 lights. One is the distant sunlight coming in the windows, and the rest are either direct lamp lights or bounce lights.