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Some tips for added realism

Posted by Marius Oberholster on Monday, September 16, 2013 Under: Tips
Hey all!

I'm not someone who specializes in realism, but I have noticed some features in Blender Render that I have been very happy with in getting me closer to realism and I'd like to share some of them with you. Remember, most of these apply to Cycles as well and also to traditional arts!

- Ambient Occlusion (AO)
A strange corner shadow phenomenon I've never really seen much of in real life on the intensity that Blender can produce, though it is a fantastic boost, even on a low setting, set on Multiply. Like here:


< Without AO - With AO >  
Quite a big difference, I'd say. The greatest, noticeable example of it I've seen in the real world is on the sides of my keyboard. Other than that, I haven't really noticed it at all.

- Environment Lighting (EL)
A very useful feature to add some softness to shapes and scenes without having to crank up lamp samples to something far and above 10. It also helps mimic those light bounces that would otherwise destroy render times for only a bit more time.

< Before EL - After EL >  
Again, huge difference, but notice on the right, there is a slight gradient to the shadow that gets darker as it goes further from the cube. Remember that environment lighting doesn't have to be set to 1 all the time. Adjust it as your scene requires. A moontlight scene can require much more than a sunny day scene would. It depends on what you want your scene to show and say.

- Indirect Lighting (IL)
In general, I would encourage people to stay away from this as far as possible, but it's not always the case for your scene. If you have a scene where you need some sort of light, like a shape that casts light, you usually need something like this. It can generally be avoided with a point lamp inside the specific shape.

< Before IL - After IL >  
I am a huge fan of this feature, despite the contradictory notion on not recommending it. Why? Because of the above demonstration. It adds something you can't really shape with a point lamp. Effective; not always. Usable; definitely. Do note that this feature is usually what causes your scene to suddenly render black. There's a bug that causes it to turn everything black where there light bounces. A solution that has worked for me once was to replace all my lights in the scene with new ones. Give that a shot if it happens again :).

- Upping light samples with an increase on Softness of shadow on lamps
Slows renders down in a big way above 5-10 samples, but the image quality is truly amazing! Give this one a try to get some softer shadows. Unfortunately, all shadows remain hard without a sample count above 1 (excluding those generated by environment lighting), regardless of soft-size adjustment.


< Before - After >  
Obviously, you can increase the shadow softness to very very high amounts, but for this demo, I simply used 3. Right click and view these at their original resolution to see the true impact softer shadows has.

- SSS (Sub-Surface Scattering)
A fantastic feature and if applied right, can add amazing quality to a scene. I've only used it well on a horn for the 4 seasons project I did recently and it really makes a difference. Be aware though that this does affect your textures and can make you lose realism, rather than gain it, so use it wisely. Here we have a cube of some sort of jelly like substance:

< Before SSS - After SSS >   
I really really like this feature a lot, but I rarely use it. Everything that uses SSS has to be rendered first and the result applied to the overall render, which can up your render times significantly. Also, when learning this feature, take your time, because at least for me, this still remains an extremely difficult one to master. For this post I wanted to use a bit in apple, but, I just couldn't get it to look right... haha.

- Mist and Z-pass
Wonderful tools, but really more for compositing. The Z-pass, often used for mist in Cycles, is a great way to simulate foggy days, create a smooth cut-off point, etc., while mist enables you to create a more mysterious or early morning type look (or even desert heat). The distance over which mist fades is a real problem for small scenes, but here the Z-pass is very useful. I don't use the mist a lot, but I do suggest you never have it start at the camera. Your field of view can become so small, it ruins the scene (scene dependent of course).


Before


    < Mist - Z-Pass >
The Z-pass is much much more customizable than the mist and the result is much faster. Do note that it does not have an anti-aliasing feature, so you may want to use a blur node to just soften the edges up a bit :).

- Translucency for leaves and other thin materials
Not a seemingly important feature, but it makes a very very big difference for nature scenes. If you hold two leaves over each other, in between your eyes and the sun (not directly, please be sensible), you'll see that the top leaf will cause a silhouette that is visible from underneath the bottom leaf. That method of light that comes through, is translucency.
Just see these odd shaped leaves below as they respond.

< Before Translucency - After Translucency >  
You can tell that the one on the right looks a lot better than the one on the left. It has more character, it's not so dark and it is just better without even trying.
Funny story: I used to apply some level of this to most of my scenes until I really understood what it was. I thought Blender was just being silly and showing light through my walls, hahaha.

- Compositing
Not something everyone is very keen on always, but this is definitely needed. For example, see how the apple isn't the focus before, but becomes so after compositing:

< Before Compositing - After Compositing >  

Do note that there is such a thing as too much compositing. In many instances, we're all tempted to shove dispersion onto every single render we make and the same with the vignette. Do not add any compositing if you don't have a better reason than: "I saw someone else do it on a scene".
   For example, an overall soft blur effect can be used to show it is very humid. Humidity, like close to the seaside, will cause a lens to fog up, giving you an overall blurry look to your pictures. In most instances you work on, this will very probably not be the case. Another use for it is to suggest memory or idyllic situations or enhance peaceful situations, like Spring's first movement. The strength of the effect depends on the scene. A lot of scenes to not need this effect at all.

- Modelling detail and bump-mapping
These form a very big part in the detail and realism of a render. Even for stylistic renders, these are a major factor. See how the apple appears with and without detail in the modelling and with and without bump-mapping:


  < With detail and bump mapping - Without detail and bump mapping >
Although these details seem small, people will know something is off, even if they can't really quite say what it is. Just look at the shape of the apple for one. On the left it is much smoother. On the right, it looks like a game engine apple with a high-res texture. Notice the small imperfections the bump mapping causes, especially to the shadow line and how it's lacking on the right.

- Post processing after compositing:
This one is not always needed, but may help your scene just a little bit. In the case above, the apple isn't very bright, but that's because I didn't want it very bright. The focus is on the apple and the scene should be fairly dark. Other viewers may disagree and say it's too dark (which I agree with overall, as the apple should be brighter). For these situations I use some editing to boost it a bit. Since I created this scene to be dark, the editing washes out a small amount of the scene, so while I think it looks better overall, I don't like washed out areas:


< Before editing - After editing >  
A very clear difference not only in visibility, but also color. The post edit image seems to have a bit of pop to it's colors, especially the red.
The apple was textured with procedural textures, not an image texture. The books I made for a previous project and so I simply inserted them for this project (the whole scene was rather empty without them). The whole image took a large part of Saturday to make, but I'm happy with it; hope you all like it too!



I hope these tips inspire you to go make something more real in Blender Render. Remember that most of these tips also apply to Cycles, so give these a try and share them with other Blender users and even those who don't! These will even help painters and sketch artists too! For further reading, check out Blender Guru's stunning presentation on the topic here!

If you tried these, post a link to your before and after on the Facebook or Google+ links to this post!

Have a great one!!

Thank YOU!!!!!!!!!!

In : Tips 


Tags: realism  improved  blender render  cycles render  render  blender  times  render times  longer  better result  try these  tips 
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