This shader is an ambient occlusion for maya software render. It was released maya 2008, 2009, 2010, 2011, 2012, 2013, 2014, 2015, 2016, 2017 and 2018 for Windows.

• Ambient Occlusion Map

Note: Autodesk Materials do not appear in the Browser if the active renderer does not support them. Not all Autodesk Materials support ambient occlusion.Used alone, an AO shader, such as the separate mental ray Ambient/Reflective Occlusion shader, creates a grayscale output that is dark in areas light cannot reach and bright in areas where it can.The following image illustrates the main results of AO: dark crevices and areas where light is blocked by other surfaces, and bright areas that are exposed to the environment.

AO looked up within a shorter radius:Using a radius creates a localized AO effect: only surfaces within the given radius are considered as occluders. This also speeds up rendering. The practical result is that the AO provides nice 'contact shadow' effects and makes small crevices visible.The following illustration depicts a model helicopter that is lit almost exclusively by indirect light. Note how the helicopter does not feel 'grounded' in the left-hand image and the shadows under the landing skids are too vague. The right-hand image uses AO to 'punch out' the details and the contact shadows. EnableWhen on, enables ambient occlusion (AO) and makes the remaining group controls available. Default=off.SamplesThe number of samples (rays) shot for creating AO.

Higher values yield smoother results but render more slowly, while lower values render faster but look grainier. Values in the range 16 to 64 cover most situations. Range: 2 to 256. Default=16.Max DistanceDefines the radius within which the renderer looks for occluding objects. Smaller values restrict the AO effect to small crevices only but are much faster to render.

Larger values cover larger areas but render more slowly. Default=4.0.The following illustrations show the raw AO contribution with two different distances.

Still Life Example Project Ambient Occlusion and Using Overlay Mode in PhotoshopThis page is designedas a supplement to lectures. It is not intended to be a stand alone tutorial.Ambient Occlusion is an indirect lighting method where the illumination of each sample point in the scene is based on the other geometry in the scene.

If there is little geometry near the sample point the value is light. If there is geometry near the point, its value will be dark. This effect creates a very soft shadow look, but more importantly it emphasizes small details evenly through the scene. An Ambient Occlusion render is typically 256 shades of gray.Many times an Ambient Occlusion render can be beautiful on its own, but usually it is combined with a more straight forward render that includes all the textures, lighting effects, and shadow.This is the rendered image using 5 lights to create a dramatic effect.

Ambient Occlusion Map

However, upon close inspection it is clear that many of the details of the objects are not clear or too dark. Also, the objects just don't appear to be grounded - sitting on the ground. Achieving a more realistic look is difficult (if not impossible) to achieve using just direct lighting methods. This is an Ambient Occlusion render of the same scene and from the same camera angle. Note how rich the detail is and how objects are very 'attached' to the ground they are sitting on. There is detail in all areas of the scene.To do an Ambient Occlusion render in Maya:.

Delete or turn off all lights. In Render GlobalsCommonRenderOptions, turn off 'Enable Default Lights'. Switch to Mental Ray Rendering. Increase the quality to 'Production'. Select the camera and change to EnvironmentBackgroundColor to what you want: Black, White, or Medium (50%) Gray. Create a Surface Shader and assign it to ALL objects. In the HyperShade under MentalRayTextures create a 'mibambocclusion' node.

Simply drag this node to the surface shader and connect it using 'Default'. Render the scene. With the default settings it will be very spotty. Open the mibambocclusion node in the Attribute Editor. Increase the sample up to 32, 64, or 128. This will increase the render time, but will smooth out the results. If you want to combine (composite) the Color Pass Render with the Ambient Occlusion Pass, you can do this quickly in Photoshop, AfterEffects or other compositing type programs.

This example here uses PhotoShop. Both images need to rendered the same size and from the same angle and same camera.

They have to match exactly. Paste the Ambient Occlusion render in a layer above the Color Pass. Change the Blending Mode to 'Overlay'. Overlay basically lightens and darkens the lower layers based on the level of gray.

A medium gray will not alter the lower layer. Brighter grays will lighten and darker grays will darken. You can change the layers opacity to soften its effect. You can also apply a Levels Adjustment t the layer to change its contrast, brightness, and darkness.