Results 1 to 3 of 3
  1. #1
    Join Date
    Oct 2005
    Location
    Santa Monica CA
    Posts
    438

    Chess4thestupid's "Things you need to know, and maybe don't."

    Hello,

    I am the lead visual effects/3D artist at a Post-House here in sunny Los Angeles California. (Although I won't say which one.)

    I have browsed these forums for a while.... and even found a few answers to questions from time to time. So thanks to all who participate.

    Anyway I've been mooching off of this and other forums for years... so time to give a little back..... I read a lot of posts asking about "how to break in to the industry?"... "What do I need in my reel?".... "What software do I need to know?" etc. So I thought..... I can answer a lot of these type of questions.

    I've attached a link to my reels on my personal site so you can get a feel for the type of work that I do.
    http://www.morecompletefx.com/reel_vfx.htm
    http://www.morecompletefx.com/reel_animation.htm
    http://www.morecompletefx.com/reel_motion.htm


    I can obviously give better advice to those looking to get into Post-Production as opposed to those trying to get more into the video game side of things... but I will do the best I can to answer any questions you might have. Since this thread will be closed I have created a response thread. All questions and comments should go here.

    RESPONSE THREAD
    http://www.3dbuzz.com/vbforum/showthread.php?p=1406797


    So without further hesitation....

    __________________________________________________ ___________

    1. UNDERSTANDING VIDEO FORMATS: Too many people come into post production, (be it animators, or visual fx artists) and know a lot about the software they are using, but nothing about all of the different formats of video/film. There are sooooo many problems that need to be solved when going between all of these different formats.... If you understand these on a fundemental level, and can solve these problems... you are even more valuable as an employee.

    Some things you want to understand are: Frame Rates / 3:2 Pulldown / Different formats of HD and SD / PAL vs. NTSC / 29.97 Drop Frame vs. Non Drop / Pixel aspect ratio. / Field Dominance.

    2. DON'T RENDER EVERYTHING IN ONE PASS: When working in post production or animation, changes come down the pipe constantly. Many times this can be less of a headache if you render things in separate passes. In some cases this just isn't a good solution but in many cases you can render elements of the scene seperately... then if they decide they don't like the tree outside the window... you just turn off the layer. Which brings me to #3

    3. KNOW SOME COMPOSITING SOFTWARE (AFTER FX / COMBUSTION): Working completely in 3D anymore is not really done. Very few people do. So many FX that would take forever to render in 3D are very quick if done through compositing software. (e.g. Particle systems, Lighting FX, Lasers, Flashes, lens flares) By doing these FX after you render, you can try a lot of different looks with relative ease, and without having to re-render in 3D.

    4. SOFTWARE "IN-BETWEENS": Programs that allow you to take positional information from one program to another are priceless as far as I am concerned. And are at the core of a lot of the high end graphics you see these days. MAX-2AE (from http://www.boomerlabs.com) allows you to take positional data from Max into After FX... for Lights, Cameras, and Helper layers. Then you can add 3D particles, text, motion graphix and Post FX easily and they line up with your 3D render perfectly.

    Plugins for After FX such as "WALKER FX 3D Channel Lighting" allow you to re light your scene after it's been rendered. The main point here is.. the more you can change and adjust without having to return to your 3D software the better. This especially applies when you are working in HD where each frame you render is 1920X1080.

    5. NEVER RENDER MOVIES, ALWAYS RENDER IMAGE SEQUENCES:
    Have you ever been 12 hours into a 13 hour render and had your system crash??? power loss??? ... and then you lose the whole movie. If you render to image sequences this never happens.

    You simply pick up where the render left off.. and keep on rendering. Because it is writing the data for each frame in a separate file a crash won't corrupt your whole render. This may seem obvious to some.. but believe me a lot of people still render to movies, and then cry when they crash.

    6. UNDERSTAND ALPHA CHANNELS and HOW TO BRING THEM ACCROSS PROPERLY:
    Alpha channels are so important in the world of compositing and 3D. Some files can contain alpha channels (tiff / targa / psd) while some cannot (jpg / bmp).

    The same is true for movie files as well. In post production almost every movie rendered out is a quicktime movie. Post production just loves this file format... but some codecs don't hold alpha while others do. In most cases when you export to a QT movie and you need an alpha channel you will use "ANIMATION" compression with "millions of colors +" selected.

    NOTE: the "+" sign after millions of colors stands for "ALPHA" -------- "Animation" is a lossless codec... so your render will look as good as it possibly can.

    7. DON'T FORGET YOU ARE A PROBLEM SOLVER:
    Many people think that in the professional world we all know exactly how we are going to do everything from the start, and that is not the case 99% of the time. For every single shot we work on there is a process of trial and error.

    Put it this way... If you know how to make a ball roll down a hill in 3D because someone taught it to you... that's great. But if you figured it out yourself because you needed it done and there was no other way... that's even better. If you want to be a valued employee anywhere in this industry... you need to be the type that can do your own problem solving. This is a KEY trait that companies look for in employees.

    8. 3D LIGHTING TIPS: Sometimes when you get a lot of lights in your scene it's easy to lose track of what each light is doing... specifically. I have a few tricks I thought I would share.

    Sometimes when placing lights in a scene I make them primary colors... like pure Green/Blue/Red this will give me a better idea about which lights are effecting which parts of my geometry.

    Every light doesn't need to cast a shadow. Of course in the real world every light does cast a shadow, but you have to remember what you are trying to accomplish with each light you put in your scene. If you don't know that... you shouldn't be placing the light in your scene at all. Sometimes you are putting light in a scene just to bring more illumination to a darker area. These are one of the types of lights that should (in most cases.. of course there are exceptions) not be casting shadows. For instance: If I was trying to light a coffee mug on a table, lit by a single lamp... and one part of my mug was a little darker than I wanted it to be (let's say the inside of the cup is too dark).... I might add a soft light just to bring out that one part of the mug. But this light would not need to cast shadows.... remember, although I am adding a light in 3D I am trying to simulate light from a single source... any new shadows would just take away from what I am trying to accomplish, and add to my render time. This can be especially costly when you have 5 lights that are casting raytraced shadows.. when only one needs to be.


    Don't be afraid to turn lights off. Many times, especially when setting up edge lights that cast light toward the camera, it is difficult to see what effect, if any, they are having. A great way to make it easier is to simply turn off all of the other lights in your scene. Then you can tell exactly what your light is doing. Also edge lights often need to be very bright to read well in your render. In most cases I use multiple lights to to get a good cast on the edge of an object and have them effect no other objects in the scene. That way I can do whatever I need to with them to get the lighting I want.. without having to ruin everything else in my scene. This is a method I learned ages ago... and I haven't stopped using it since.
    Last edited by chess4thestupid; 03-15-2009 at 07:58 PM.

  2. #2
    Join Date
    Oct 2005
    Location
    Santa Monica CA
    Posts
    438
    PRINCIPALS OF LIGHTING PART 1
    View this post with text and images together here : http://www.morecompletefx.com/tut_pricipals_01.htm

    I have seen all kinds of tutorials on the web for modeling, rigging, texturing, and everything else under the sun; but I have yet to see one on lighting. Not how to USE lights, but how to light a scene so it looks good. I've seen too many great models and scenes DESTROYED simply by bad lighting.

    (NOTE: I use 3D Max, so this tutorial will be done in Max, but I encourage anyone doing 3D in any program to give it a read. 95% of this tutorial deals with concepts and principals of 3D lighting that will translate to ANY software set.)

    If you come from a film background and have done any "real-world" lighting, then you will have a head start.... but you must remember, 3D IS NOT the real world... so when lighting in 3D there are many different things to consider.

    I want to quickly talk about the difference between lighting in 3D and lighting in the real world. When we start a scene in 3D we are starting with absolutely ZERO light. In a real world scenario we would in all likelyhood have some ambient light no matter where we were.

    This is great for us... because in 3D we start with no light whatsoever... so we have total control over the lighting of our scene.

    On the other hand if our scene is not lit properly it's easy to have very dark areas.. and often unrealistic shadows in our scene... which is a a quick way to make your renders look like crap.

    Section #1
    http://www.morecompleteproductions.c...als/img_02.jpg
    One way you might try to fix this problem is by adding "Ambient Light". This type of light is an environment setting in 3D MAX (RENDERING > ENVIRONMENT) and most 3D software has an equivalent. When set to BLACK it transmits no light, but change this to a gray or any color and you start to get a little light in your scene that fills in your dark shadows. (EDIT: I am ONLY talking about the ambient light setting in the environment dialog. NOT ambient light settings in materials and lights themselves.)

    http://www.morecompleteproductions.c...als/img_03.jpg
    This is a bad idea. In most if not all cases you should avoid using Ambient light altogether. ( I can only speak for 3DMAX in this case.) You have little to no control over it, it doesn't represent the real world equivalent at all, and it is applied evenly across your entire scene. Look at the image above. In the second image where Ambient Light has been added it has removed the darkness of our shadows, but it has done it evenly across the entire render.... the shadows don't collect where the sphere comes in contact with the ground anymore.


    Section #2
    For our first scene we'll do something ultra-simple so our render times won't kill you.... and I don't think you can get any more simple than a sphere resting on a box. If you want to follow along in 3D MAX... feel free.

    http://www.morecompleteproductions.c...als/img_04.jpg
    (I have added default blinn textures to both the sphere and the floor, and lit the scene with one TARGET SPOTLIGHT casting shadow mapped shadows with a multiplier of 1.5.)

    So lets start to look at this dark shadow area, and how we can go about fixing it.

    Most people have heard of "3 point lighting" consisting of a KEY, FILL, and BACK light.... but this works a little different in 3D. The spotlight I already have in the scene is my KEY light.

    What you are looking to do with your FILL light is to to "fill" in the super dark areas in your scene and bring out the detail in your shadows.In this case I will use an Omni light with a multiplier of 0.2 to "fill" the shadow areas with some light. In most cases your FILL light will have much less intensity than your KEY light.

    In this next image you can see the subtle difference in the highlighted areas. Now we can see the back side of the sphere. How much fill you choose to add to your scene is obviously up to you. But in this scene I am trying to achieve a dramatic spotlight effect so I'll leave it where it is.

    http://www.morecompleteproductions.c...als/img_05.jpg
    It's important to notice my fill light is casting no shadows. Now I'm not saying your FILL light should never cast shadows, but don't think just because a light would cast shadows in the real world that you must have every light in a scene casting shadows in order for it to look good.

    In fact when you start to cast too many shadows in a scene you can begin to get a cluttered look... but we'll get into this later on.


    http://www.morecompleteproductions.c...als/img_07.jpg
    Let's move on to the BACK light. This might surprise you but your backlight is usually much stronger than any lights in your scene. In Frame #1 I have added a backlight with a multiplier of 10... remember our KEY light was only 1.5. As you can see I now have a nice highlight on the back of the sphere but my floor is blown out. This may scare you and make you feel you have done something terribly wrong... no worries... simply have your BACK lights exclude illumination and shadow casting on the floor.


    Now look at Frame #2, I have retained my highlights on the edge of the sphere without destroying the rest of my scene. Remember... ultimately you have total control over what your lights do and do not effect... so take full advantage.

    In Frame #3 I went ahead and added another backlight coming from a slightly different angle to give my sphere a longer highlight around it's edge. Sometimes you may find you need to add many backlights to a scene in order to get the result you are looking for.

    I could go deeper into these principals but this should give you enough to get started thinking about lighting your scenes with a little logical thinking instead of just placing lights in the scene and hoping you can get a good look.


    I'd like to touch on one more subject before I move on to the next scene.. and that is shadow density. 3D MAX has this setting in the "modify" panel for your light.
    http://www.morecompleteproductions.c...als/img_09.jpg


    http://www.morecompleteproductions.c...ls/img_010.jpg
    I have removed all but the KEY light for this example. In image "A" I have left the shadow density at 1.0 and in image "B" at 0.5. Notice how area #1 in both renderings is the same... but area #2 is much lighter in image "B". This is the problem with lightening your shadows by density. It only changes the density of "cast shadows" not shadowed areas of the geometry. In short it is very hard to achieve a convincing render with low shadow density values.


    Section #3
    One thing that effects your ability to light your scene is your model itself.

    http://www.morecompleteproductions.c...als/img_01.jpg

    I have lit this scene with only one omni light and am casting no shadows because we only want to look at the specular highlights on the three boxes.

    The first box is a standard flat 6 poly box while the following 2 are "chamfer" boxes. All three boxes have the same material applied to them but notice how they respond to the light differently. In our everyday world nothing has a dimensionless edge like the first box, look around you, counters.. shelves.. chairs.. they all have a rounded corner.

    Without this rounded edge you will never catch a specular highlight on the edges like it would in the real world. So the lesson here is you should almost never use just a plain box, use a chamfer box (or chamfer your edges later) and make the "fillet" small like box 2 if you want to make anything square or rectangular.

    You should also take this into consideration when modeling complex geometry as well. If you want to see specular highlights, you have to give your model someway to react to them.

    FINAL THOUGHT
    My scene I've done here with a sphere isn't a great looking render... but the final result looks better than a spotlight alone... while retaining the same effect. I've kept it simple because I am trying to illustrate lighting principals here and don't want to clutter up the fundamental concept with materials/final gather/raytracing etc... and all those kind of things.


    THINGS TO REMEMBER

    1. Avoid using the AMBIENT light setting in your scenes. (EDIT: I am ONLY talking about the ambient light setting in the environment dialog. NOT ambient light settings in materials and lights themselves.)
    2.Avoid lightening your shadows with shadow density.
    3. Remember all lights do not need to cast shadows in order to achieve a great render.
    4.The Principals of 3 point lighting can be applied to ANY scene.
    5. All of these rules will be broken from time to time... but are true 99% of the time.
    6. You can make bad models look good with proper lighting.
    7. You can make good models look bad with bad lighting

    MORE TO COME.....
    Last edited by chess4thestupid; 03-21-2009 at 05:23 PM.

  3. #3
    Join Date
    Oct 2005
    Location
    Santa Monica CA
    Posts
    438
    PRINCIPALS OF LIGHTING PART 2
    View this post with text and images together here :http://www.morecompletefx.com/tut_pricipals_02.htm

    In this "installment" I'm going to put into practice some of the things I've talked about in my initial post.

    Harsh shadows are a great way to make your renders look like crap. Sometimes they are the right look for a scene (moonlight, bright day outside with no clouds, flashlight etc.) but in many cases that is not the look you want.

    In this scene I have placed a teapot on a shelf using the lamest textures ever conceived by man to illustrate how much you can improve a scene just with lighting. I will be using the principals of 3 point lighting although I will be using 16 different lights in the end. Remember 3 point lighting doesn't mean only use three lights. 16 lights sounds confusing... but if you know the purpose of each light you are placing... it is easy to manage and makes a lot of sense.

    http://www.morecompleteproductions.c...eapot_01_A.jpg
    http://www.morecompleteproductions.c...eapot_01_B.jpg
    Here is my scene.. 1 spotlight intensity 1.0... and it looks like crap. (KEY LIGHT)



    http://www.morecompleteproductions.c...eapot_02_A.jpg
    http://www.morecompleteproductions.c...eapot_02_B.jpg
    In this step I added 2 spotlights lights as FILL LIGHTS to reduce the harshness of the shadows... behind the teapot and under the shelf. intensity 0.2



    http://www.morecompleteproductions.c...eapot_03_A.jpg
    I talked about this in my initial post. In this step I have colored the lights harsh primary colors... this way it is easy to tell what geometry the lights are effecting and where their influence begins and ends.



    http://www.morecompleteproductions.c...eapot_04_A.jpg
    http://www.morecompleteproductions.c...eapot_04_B.jpg
    I have added a BACKLIGHT in the form of a spotlight (intensity 10) and colored it blue.. once again to help me distinguish it from the other lights in the scene. Now I have a really good idea as to what each light is doing.



    http://www.morecompleteproductions.c...eapot_05_A.jpg
    Now I have changed my lights back to their original colors (in this case white)... but I still have harsh shadows. Here is where I add the other 12 lights.

    BUT WHY?

    In the real world light never emits from one small point like a spotlight does in 3d MAX. Light is emitted from larger sources.... light bounces around... and casts from many different angles although it may be coming from one direction. So how can I simulate that? I will clone (as an instance) my KEY LIGHT 12 times (each scene is different you may want more sometimes... sometimes less). You can do this with an array or by hand... I usually do this by hand.

    http://www.morecompleteproductions.c...eapot_06_A.jpg
    http://www.morecompleteproductions.c...eapot_06_B.jpg
    Finally I made the intensity on all of the clones 0.1. Since there are more lights I can't have each one casting an intensity of 1.0.. this would blow out my entire scene.


    FINAL THOUGHT
    Once again the final render is not the world's greatest rendering of a teapot.... but if you compare the final version to the first render you will see a vast improvement in the quality of the shadows.
    http://www.morecompleteproductions.c.../Teapot_07.jpg
    You can see how I started simple with just a few lights and then added more in a logical manner. In the end I had 16 lights but they were all serving a purpose and not just thrown in there haphazardly.... and I was using the principals of 3-point lighting the entire time.

    I also forgot to mention that the only lights casting shadows are the 13 KEY LIGHTS.... it is the crossing over of their shadows that makes the softer shadows in the final render happen.

    KEY LIGHT (13 lights)
    FILL LIGHT (2 lights)
    BACK LIGHT (1 light)


    THINGS TO REMEMBER
    1. Harsh shadows can make for an unattractive render in the wrong scenes.
    2. Place your lights in a logical manner
    3. Coloring your lights can help you see what they are really doing in your scene.
    4. 3-point lighting doesn't mean only use three lights.
    Last edited by chess4thestupid; 03-21-2009 at 05:24 PM.

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •