Blend modes in Software

Drawer Quick Response Code in Software Blend modes

attributes Maya provides a preset render layer setting that creates the appropriate overrides to the render settings: right-click the layer and choose Presets | Diffuse Name this layer diffuse and render it in the render view You will notice that the specular highlight is not visible anymore You can select the master layer and render that to see the original setup and compare the two images Any override to the Render Settings window will be indicated in the Render Layers window by the Render Settings Override box being active

Select only the two pieces of geometry and create a new render layer Name this layer occlusion An occlusion pass is sort of a rendering shortcut to obtaining shading results commonly associated with Final Gather Instead of calculating photons, occlusion uses raytracing to sample points around a pixel and determine whether or not the pixel falls in shadow If it does, then the pixel is shaded black (by default); if not, it renders white The gradation between the two can be determined by a falloff value The Mental Ray shading library contains shading nodes that allow you to set up a shading network to render occlusion passes Once again, however, Maya contains a render layer preset RMB-click the occlusion layer and choose Presets | Occlusion Both the Override Shader and the Render Settings Override icons become active If you look in the Hypershade, you can see that Maya has created a new Surface Shader with a mib_amb_occlusion node connected to it and has applied this shader, shown here, to all of the objects in the scene

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When you look in the view window, everything appears black, indicating that the Surface Shader has been applied to the objects However, if you were to click the diffuse layer in the Render Layers window, you would see your diffuse shaders Since the occlusion pass uses Mental Ray shading nodes, this pass must be rendered in Mental Ray By selecting the occlusion layer and opening the Render Settings window, you ll see that the current renderer is set to Mental Ray and that many of the settings are highlighted in orange to indicate that they are being overridden Rendering this layer will produce an image like this:

On each shape node, there is a folder called Render Stats that contains flags that tell the renderer how the object will behave in the renderer Will it be visible, not visible, or visible but not in the reflections Will it cast shadows Will it receive shadows By turning on and off the flags in the Render Stats folder, you can control any of these functions We are going to create a new render layer that will render just the shadow While this type of pass does not necessarily require a render flag to be overridden, we will make one small adjustment to optimize the render Select all three objects (the two geometries and the spot light) and create a new render layer RMB-click and choose Presets | Shadow Name this layer shadow While everything is set up for a perfect shadow pass, we will make one override One thing that can speed up render times is setting the ground plane to not cast a shadow Otherwise, Maya needs to generate a shadow map for everything in the path of the light We can optimize our render times by making an override While there is a Member Overrides button available to us in the Render Layers window, we don t want to make the override on the entire layer, but only to the ground plane This means that we will make a manual override Select the ground plane and view the shape node s attributes in the Attribute Editor Find the Casts Shadows check box and RMBclick Choose Layer Override from the marking menu as shown here Disable the check box The ground will no longer cast a shadow