As you can see I’ve moved my lighting tutorial to my new blog. This tutorial is pretty out of date, I believe I was using maya 8.5 at the time, but it still gets a lot of hits so I’m keeping it around. I’ve updated this tutorial as a step by step video that I did for the students at iAnimate.net for their graduation at DreamWorks. Sorry, this is a recording of a recording so the quality isn’t great, but all of the information is there to get you started lighting your shots using image based lighting.
This video is best watched in HD on Vimeo, and if you watch full screen turn scaling off.
Hey everyone….I received a lot of comments about the render on my baseball shot so I put together a little tutorial on how to do it.
My little disclaimer up front….This is an easy way to get a nice bounced light effect in your renders plus some really nice occlusion….I am not a MR expert, If anyone is a MR expert and would like to add suggestions feel free!
Ok, so here goes.
IBL for Animators
IBL stands for Image Based Lighting…its an option when rendering with Mental Ray. I’m going to share with you my MR(Mental Ray) settings and the steps I took to light my shot. First I use this method because A. I like the results B. I’m not a lighter but I still want my shots to look good and C. I don’t like spending a lot of time stetting up lights, but I do have time for it to render over night. WARNING: MR renders can take a loooong time.
First thing you will have to do is change all of the shaders on Bishop. His default shaders are old and do not work in MR. If you leave them you’ll have a glowing Bishop. Next when swapping shaders(I won’t go into that here) make sure to turn reflectivity off. For his head and body I used lambert and the eyes are phong.
So here is our Maya scene all ready to go….Click on the images to see them larger.
This is what the shot would look like if we just hit render.
Now lets setup MR. Open your Render Globals and choose Render Using: mental ray. You will see a new tab appear named mental ray. First I set the Quality Presets to: production. After that I change values and that will change to read custom, but its a great way to start…it does some of the work for you.
These are the settings and values that you will change:
-Number of Samples
-Max Depth 20
-Shadow Depth 2
You will also see these settings in the image above.
Now expand Final Gather and check the box to turn it on.
-FG Rays 500
-Falloff Start 0
-Falloff Stop 0
-Trace Depth 2
-Trace Reflect 1
-Trace Refract 1
-Secondary Diffuse Bounces
Thats it! Now for the IBL. Expand Image Based Lighting and click create.
Now you will see a huge sphere in your maya scene….if your sphere comes in too large and you can’t see it, zoom out till you can and scale it down till it is just a bit larger then your scene.
Now lets see what IBL is all about. Select the sphere and open up its attributes. Change Type to Texture. Change the Texture color to white. Your render will look like this. Lots of bounce white light throughout the scene.
What Final Gather does is shoot light rays into your scene and they bounce around. If you look closely you will see the blue on his jeans also bouncing onto his arms and the bleachers. Also a very nice feature with MR is the ambient occlusion. Really simply…you will get nice dark areas where geometry is close to each other…in this render you will notice it the most where his butt touches the bleachers.
To further illustrate this point of bounced light, change the white to red. Now your render will look like this.
Now set it to 50% gray. Thats a really good starting point and as you can see by this render, that looks pretty good.
You can get away with a clean simple look just by adjusting the color and adding one or two lights. The point is to not muddy up a scene. The characters look simple, the lighting and sets should match.
IBL stands for “Image” Based Lighting right…so what about an image. Well thats what we are going to do next. I knew I wanted some bounced green light from the grass below him and some bounced blue light from the sky above him. So I found a photo that had those elements and adjusted it in PhotoShop to look like this.
As you can see it doesn’t look much like a photo anymore….these will be wrapped on the sphere so its important to make sure you get the colors in the correct spots. I start with a photo, or a painting of mine, rather then using a ramp because you can get more color variation within your major colors. Also it takes time in this step to get the saturation and color just right.
To add a file just select the sphere. Change Type to Image File and click the folder button next to Image Name to link to the file. I should mention its very important to create maya project files. You should store your images in the sourceimages directory. Now the render looks like this.
Ok so that is looking about how I want it…now to add detail. How do we do that? Lights!!
The final render has only two lights…the IBL gives you so much that you really only need one light to act as a source(such as the sun) and to cast shadows.
My audio has some birds chirping in it so I thought that there should be trees around. I decided to add what I call a Canopy light. Its just a light that has an image mask on it to give the appearance of light coming through a tree. I start by creating a spot light. I select the light and then choose Panel – Look Through Selected. That way I can position the light by looking though it like a camera.
Next I open the lights attributes. First I select the box next to Color. A new window will open up and I select file.
Then I select the folder button next to Image Name. A new window will open and I select my canopy image.
My canopy image looks like this. The file works best in gray scale.
Now lets change the lights attributes. I set my Decay Rate to Quadratic…it has a shorter fall off and I like a nice hot spot. After you change that, turn on Raytrace Shadows under Shadows. Last but not least is to adjust your Intensity. Intensity is very different with Quadratic Decay so you will set this value much higher then your probably used to. This will be some back and forth, rendering out to test as you go. As you can see my Intensity for this light is set to 11000.000. You can see the result in the render below.
Now this scene feels like there is more to it off camera and we are starting to get some mood. The only thing I don’t like is his face is too dark…Time to add one last light.
For just a beauty light I chose a point. Similar settings as before, Quadratic decay…but this time no shadows and no image file. As you can see below I set my Intensity to 33.000, I just want this to be a subtle soft light on his face. Also I like to adjust the placement of the light by hitting 7 in maya so I can see a rough estimate of the results.
The render looks like this.
Alright, just how I wanted…now its time to render and composite….but one last thing before I do that. Turn off Primary Viability on the IBL. Select the IBL sphere, open its attributes. Under Render Stats un-check Primary Visibility. This will give you a nice clean alpha for your composite.
I rendered my shot out and composited it in Adobe After Effects. Two layers….my render and a background image I created in PhotoShop. I took a photo of a baseball field and blurred it out and adjusted the color. I also added a shadow of our fake tree. You can see my PhotoShop layers below.
So thats it!! This is my first tutorial so if anything needs clarification just let me know. If anyone would like me to go further in depth on shading, compositing, or any other area that I left out in in this tutorial I’d be more then happy to write more. Please, comments and suggestions are very appreciated. Remember we are not here at AM to be great lighters, don’t spend homework time on this….If you really like it, on our summer break, if you need a rest from animating, mess with it then. I’d start with a simple scene with a sphere on a plane.
If you would like to see more examples of this check out my demo reel. All the renders were done with this exact same method.