Green Rascal Design

 
 
I've been scratching around for other modeling classes to teach, and I may have found one at an unlikely source for the summer. This could be really interesting - teaching non-architecture students how to model in 3D. The concepts are all the same, though, so I can see myself doing it as long as the students are motivated.

:)
 
 
This is just a shout out to everyone starting a new term at Philly U. And if you're in structures II, my friend Professor Billings is teaching a section of that this semester!

I'm spending my time in the coming weeks on a new lesson plan for next semester. I'm hoping to be back with a better structure after seeing feedback from last semester. Naturally, my lecturing skills need improvement. But I'm told that is normal for a first semester of teaching. Thanks for the feedback!
 
 
I went over render setup with most of the students previously, but everyone needs a little refresher, it seems. If you haven't spent a lot of time messing around with different settings it can be really hard to remember what everything does and all the different places to go to change things. So here are a few basic areas to pay attention to. We'll start with the Common tab, and right now we're using Mental Ray.
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Output Size
Pay attention to your Output Size. If you're going to plot out your renderings at a large size this can make or break you. 640 by 480 is great for testing things out, and it's what I've been using for these tutorials, but it would look terrible printed at 11x17. The resulting image size, photoshop tells me, is about 14" by 23" but the resolution is only 72ppi. For presentations I'd much rather have 300ppi. Over the web it would be hard to show the difference, but it's huge. So I always bump the Output Size up to at least 800 by 600. Actually, in the past I've done my screen resolution (1200x2400) but that's because I was working on my own computer or sending my files to the render farm. In the computer lab, where space and time matter, this isn't a nice thing to do to your peers.

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Options
Now briefly look at the Options. What I do here is make sure Force 2 Sided is checked on. Here is the catch-all for surfaces with backwards normals that might appear invisible in renderings. Sometimes bad things still happen when I have this checked, but it does help a lot to have it on.

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Advanced Lighting
Moving on to Advanced Lighting... These two little check boxes can save you some time or make things look more or less realistic. Advanced Lighting is good in my opinion. I always have Use Advanced Lighting on. To save memory in my computer I like to check Compute Advanced Lighting when Required. This means it will process the scene when you tell it to render, not every time you make a change.

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Global Tuning
In the Renderer tab, check out Global Tuning. I don't usually mess with these settings, but you might want to know how to make shadows more precise or softer. These are set to .5 by default on my system, and it's a good setting. Making the multipliers 1 will add time to your rendering, but they will be more precise if that's what you want.

I don't usually mess with other settings in the Renderer tab.

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Final Gather Basic
In the Indirect Illumination tab, Final Gather is very important. I always want to check Enable Final Gather. I leave the multiplier at 1. For drafts I put the slider that says Presets to the left, or low. For final renderings I use high or very high. For most things I don't bother touching any of the other controls except Diffuse Bounces. Default it 0, I believe. I always set it at 1. Higher numbers like 2 or 3 will make the light bounce around in the model more, and it will soften the rendering. If you're having a problem with things being too crisp, try 1 or 2 Diffuse Bounces.

Advanced Final Gather options such as noise filtering can be adjusted if there is a lot of noise or speckles in your renderings. I usually don't mess with these things.

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Caustics and Global Illumination
Caustics and Global Illumination are extras that I don't usually use either. They can add more reality to your rendering, but they also can add time and processing power. Also, Global Illumination is seen as a way of cheating by some fanatics because it lightens up your scene artificially. If you are doing accurate light studies this isn't for you. That said, it can't hurt to try them out someday when you're bored. There is plenty to read in the help file about them, too.

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Processing
The Processing tab is all about files and memory. Sometimes I check the box by Conserve Memory. The following stuff I don't bother with. Geometry Caching you can read about. I think it improves performance. If your file is crashing a lot it might be worth it to check this box. That's the only thing that I think might be useful to the class at this time.

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Render Elements
The Render Elements Tab allows you to add atmospheric effects and other fancy things. I'm sorry we haven't had time to go over these things this semester, but it seems like nobody is really in need of them at this point. I usually don't use them anyway.

If you are not using Mental Ray your tabs look different! Remember if you switch renderers under the Common tab that the tabs all change and rearrange themselves. Here's what is different.
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Radiosity
Now there is an Advanced Lighting tab. Here I have Radiosity selected in the drop down. The other option, Light Tracer is good for some exterior renderings, as I've said, but most people don't use it for much. Radiosity seems to be the preferred way to go these days. Years ago this was not the case, but you can read all about it elsewhere.

Radiosity Processing Parameters provides a few buttons that allow you to reset your radiosity solution. If you make a change to some lights, you can hit Update & Start to see the new lighting solution. The progress bar is there to show you the calculation time.

Under Process you can turn up Initial Quality. Default is 85%. Sometimes I turn it up to 90% or 95%. This makes renderings take longer, but they look better. Check the box that says Update Data When Required on Start. This will help a little with memory.

The Interactive Tools allow you to brighten things up a bit by bumping up Indirect Light, or soften things a smidge with Direct Light Filtering. I rarely use these things. The Logarithmic Exposure Control Setup button takes you to the Environment box. I like to check Display Radiosity in Viewport, as I've said. But it only shows in viewports that are set to wireframe, as you can see.

Radiosity Meshing Parameters I have talked about. Enable Global Subdivision, and you can control the size of the mesh here. This effects the smoothness of light hitting and reflecting off surfaces.

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Rendering Parameters
Rendering Parameters are important. Here is where you tell Max to Render Direct Illumination and Regather Indirect Illumination. I don't usually change the number of rays or size of the radius. Sometimes I do check the box by Adaptive Sampling. This changes the density of shadows, and you can change the spacing of samples here. Sometimes I change the Initial Sample Spacing to 8x8, but this adds time. You can play with this sometime.

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Raytracer
Finally, I don't usually touch the Raytracer tab. Global Ray Antialiaser can help blotchiness. Everything under Global Raytrace Engine Options comes enabled by default, and I haven't found many reasons to change them. Show Progress Dialog helps if you need to know what's going on. It's all pretty basic.

I'm gone over all the sections I think my class needs to pay attention to at this point. Hopefully these notes spark memories of stuff we talked about in class!
 
 
Today I'm going to put up an example of the photoshop I was talking about on Tuesday just for fun. The four following images are from one camera.
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radiosity, lights high
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mental ray simple, lights high
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radiosity, dimmed lights
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mental ray, 3 light bounces, final gather, mr physical sky on...
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I started out by putting all 4 images into one file. Then I moved the last one to the top layer because I want to make sure the physical sky shows in the final version. This image shows the bottom layer as normal and the mental ray layer above it set to luminosity to brighten it up.

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Then I turned the radiosity layer above that on, and to smooth out the table I set it to divide and turned down the opacity to 50%. This made a very slight smoothing difference in appearance.

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Then I used the last mental ray rendering with that sky background on multiply to make it less bright and add some depth with an opacity of 50% to not make it too soft.

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So there is the comparison. On the left is the best quick rendering that 3ds Max gave me in under two hours. On the right is a combination of renderings I made in photoshop that brings out the best in each one. This is really really fast and simple, and I know it still looks a little fake, but it's an example of how you can take some less than perfect renderings from Max and make a much better one with very little trouble. A little light erasing here and blurring there, and you're right as rain. See, no reason to get upset if things aren't perfect the first time. After all, rendering is really an art and you can't expect your modeler program to do it all for you.

That's all I can fit in on this today. Send questions or complaints if you like.
 
 
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I figured I'd post an update on this project. The image is a combination of 3 different renderings, and I did not do ANY photoshop touch-ups. They are simply different blending modes layered on top of each other with different opacities.

Now this still looks a bit fake. However, I submit to you that this whole thing took me 3 hours. That includes re-importing the updated AutoCAD model to 3ds Max, creating all new materials, setting up about 41 new lights (not all in this one room) and rendering 6 different cameras in 4 different ways each, then combining the 4 images of this camera into the jpg you see. With a lot more time, such as students have, this could look much more realistic.

Everyone in class has a lot going for them. They've spent weeks making their models. They took days tweaking their materials. They agonized over lighting for hours. They pondered rendering settings and advanced lighting modes for only GOD knows how long. Things are looking pretty good. Now is a perfect time to talk about adding some touches in photoshop to make things look much more realistic.

A bunch of the students in this class say they're really good at photoshop. Some others maybe need more help. I haven't really figured out a good starting point for touch up lessons yet, so I won't go on and on here today with anything specific. In class later I want to talk about who knows what, and go over some basic stuff with anybody who needs it. For those with more advanced knowledge, I want to see some proof! Let's get those people inserted!

It's been a nice long weekend, and I hope everyone is refreshed now! See you later.
 
 
For our last class before the holiday season begins, we'll be working on pumping out those renderings.

If you searched for mental ray versus radiosity or similar in Google, as some of the students like to do, you would find a huge debate over what renderer is better, etc. I have been forming my own opinion, but there are always exceptions. This is why answering some questions in class is tricky and I promote the idea of experimenting. However, the lecture today will go over some of my thoughts on this debate. Then we can go off to our long weekends and ponder implications until Tuesday.

That's it. See you later!
 
 
Usually I don't bridge business projects with tutorials, but it just so happens to be the perfect time to take this into production. The other day I briefly talked about meshing with respect to producing renderings. Class seems to be lagging a bit, however some people are itching to get into photoshop with their projects. Naturally, we're here to learn how to pump out renderings in Max that require as little post-production editing as possible. I'll work on this today with respect to my current office project. (Surely the clients would approve since they're in the business of helping people.)

I confirmed recently that sometimes you have to place lights outside of their fixtures in order to get them to show up the way you want. All the artificial light in this model is therefore placed strategically above or below the fixtures. If your test renderings are not showing your lights properly, try adjusting their locations, angles and targets.
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Now, about radiosity. Remember that in order to get to advanced lighting, you have to change the renderer to scanline. This is under Render Setup > Common > Assign Renderer. Changing back and forth between renderers might do unexpected things, but I find it to usually turn out for the better. What looks black and dead in mental ray can look much livlier in radiosity, and vice a versa.

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Also, sometimes I change to radiosity and it looks horrible so I change it back, only to discover that now my mental ray looks better than before I tried radiosity. If I were a scientist I'd have a reason to offer for why this happens, but all I have at this point is a guess that the radiosity mesh has lingering effects.

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Clearly the mesh is still there when I switch back.

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very slight changes
Now I have a new mental ray rendering. It still looks somewhat dead, but it's better than before. It certainly is better than my radiosity rendering was for some reason. I'm going to spend some time adjusting lights and stuff, return to radiosity and tighten up my mesh, and then see how it looks again. Welcome to the second most time-consuming part of modeling. (Or it could be the most time-consuming if you have become pretty good at making stuff.)

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I'm also going to turn different things on and off like a volume light, exposure control, shadow types and a soft filter on the renderer. After I collect several different kinds of renderings from the same camera, I can layer them in photoshop which is easier than coming up with stuff out of the blue sometimes. This can end up as one of my smaller renderings. When I get a good feel for how the renderings are coming out, I will increase settings such as quality and output size for my showstopper rendering(s) eventually.

To address the question of, "how do I make my rendering look like a photo," the answer is to add more detail. This room looks dead because I have no papers lying about like a real office. I don't have any paintings on the walls or family photos on the receptionist's desk. I don't have a wall hanging for brochures or anything. I can't add these things now, but at some point I know that I will have to if I want this to be realistic.
Right now try to get Max to provide you the most believable renderings you can. You will need to move on quickly now if you plan to make things realistic with details and other things, whether they be in model form or in photoshop. Hopefully you have camera angles you are happy with so you can come back to the same views later if you have time. Enjoy!

 

Meshing

11/16/2010

0 Comments

 
I want to talk briefly about meshing radiosity today. A lot of students think, "well why should I do all this work if mental ray does it for me and everything looks okay with that?" Hey, you're right. It is some work, but this is valuable to know so that you can picture what is going on when the computer does all those computations for you. This concept applies to object properties too.
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This is what my radiosity mesh looks like with a maximum mesh size of 3'. The resulting rendering is okay, but a little splotchy.

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Here is my radiosity mesh with a maximum mesh size of 2'. The resulting rendering is much smoother than previously. You just have to take my word for it.

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Here are the main areas where you can tell the difference between the two meshes. The finer mesh is lighter because I have overlaid it on top of the large mesh in photoshop. I just thought this would help you picture the point of meshing.

We will talk more about this later. It is key. And the faculty want to make sure that all the students understand meshing because, after all, this is supposed to be advanced modeling, and meshing is a basic advanced concept. Basic advanced, does that make sense? Ok, enough joking around. See you later.
 
 
No, I don't mean the show.
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Here's a nice little guy I got for free online. If you have a simple model, and you want to go the route of adding 3D people to it, then that's fine. I don't know how to make people in 3ds Max yet, so I can't say how long the artist took to make this guy. Though I'm glad I found him, and he works great for this simple model. I would not, however, add a lot of 3D people. If you have something that needs a couple of main characters, this works. Once you get the feel for how light is reacting with one or two of these types of objects, you can probably get the same results with Photoshop.

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Here is a version of the rendering with an additional person. She's not quite as awesome, but the thing is pretty fuzzy so it really isn't that visible. I messed around with the radiosity parameters, and I'm not that happy with it. The point of this image, though, is just to demonstrate adding more people to a rendering. See below where I have added two flat people in photoshop, and I only spent half an hour on this at most.

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If I'd really planned this out, I might have picked images of people that weren't so sharp and detailed so that they might match what I already had going on. That's okay. The point is clear. Notice how the space feels with more people in it? It went from being a lonely room last week to some guy admiring a statue, then to a guy and his wife arguing about the statue, and finally to a room where a bunch of people are discussing the statue.

Now is a good time to think about how you plan to populate your models. Collect models or images of people that seem to fit together with each other in addition to your space. How many people use your place on average? What are they doing there? This is your entourage, and just as you'd carefully select friends to hang out with, spend some time selecting  them for your projects! (Certainly spend more time than I have today!)
 
 
Time to talk about lighting, environment and rendering settings:
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These are 12 different renderings (not in order of creation) exploring only a few variables. You may recognize some problems you are finding in your own progress renderings, and hopefully we can talk about that this week. For today we should focus on identifying what style you would prefer to achieve. Everyone says "I want my project to look like a photograph." Well, have you ever taken a photography class? If not you might be surprised to find out how vague your goal really is. A real camera can give you a very wide array of results! It just so happens that in the 3D world the way you achieve the same thing is by manipulating things other than aperture size, F-stop, shutter speed and time of day or lighting levels. If only we could just say, "I want this to look like an aperture width of 2, an F-stop of 8, focused at infinity, with a 28mm lens, slightly under-exposed on a cloudy day at 2pm," click. Oh, what film type was that? See what I mean?

Anyway, think about what you're getting now and what you'd like to achieve. I'd like to say we'll have a lecture on Thursday about this, but to get the class going it might have to be today depending on where everyone is at with those darn materials. We should try to keep in mind that the materials will look different under altered rendering settings, and perhaps this is the perfect time to switch it up.

This particular model has one basic material in it, and it looks fairly different when I change the shadow type, etc. And if you're curious, I was working on making an environment effect, so I have two suns and two skies, all with different properties but in the same location, under different activation combinations... and I changed render engines once, environments a couple times and shadows all different ways. As long as you keep notes while messing around I encourage doing several studies like this.