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Thursday 22 March 2012

Baking Ambient Occlusion map in Maya


                                   Baking ambient occlusion map in Maya

We are here to discuss about ambient occlusion map. If we want to give more details to our scene than ambient occlusion map can help us. Ambient occlusion map gives more depth to our scene. Baking ambient occlusion map is simple and easy. We are going to bake ambient occlusion map with the help of mental ray.

Step1: Create a model and unwrap it. When we are going to bake ambient occlusion map than we have to keep one thing in our mind is that overlapping of UV's is not allowed here. We have to avoid overlapping of UV's. If you don’t do this your A.O map will not be accurate.




Step 2: Now go to render settings and select mental ray. If mental ray is not showing in render settings than load it form plug in manager. For this go to windows and select plug in manager it will open a dialog box. Now choose Maya to mr.mll and click ok. Again go to render settings and choose mental ray as renderer.



Step 3: In rendering menu set go to windows than rendering option and select hyper shade. Choose surface shader here. Now click to texture under mental ray tab and select mib_amb_occlussion. In work area select mib_amb_occlussion texture and with the help of middle mouse drag and drop on to the surface shader and connect to default.





Step 4: Now apply this shader to the selected objects. It will make all the objects black coz surface shader has no color. Render the scene you will get some noisy image like this (image 3).

                                                                                  (1)
(2)

                                                                          (3)

Step 5: let’s see how our A.O map looks. For this we have to check the quality and adjust few settings. First adjust the sample rays to reduce the noise. Adjust the spread amount. This is the parameter from which you can control the width of your occlusion. normally at spread value of .75 is good. If you required than use max distance. No need to change this right now.




Step 6: Now we are ready to bake our A.O map. For this choose rendering menu set and under the lighting and texturing tab select batch bake mental ray. It will open a dialog box.





Step 7: In this dialog box just feed the details like objects to bake, bake shadow's, use bake set override, color mode, occlusion rays, prefix, file format and seam etc.







Step 8: click convert and close. A.O map is baked and save under the mental ray folder. To see A.O map go to project folder than metal ray and here go inside light map.



This is our baked A.O map

Step 9: Now we have to use our A.O. map. For this open this A.O map in Photoshop and place this layer on top of the color map in multiply mode. It’s very important to put this layer in multiply mode. Now you can see the depth in your color map. Apply this to your object and render.



                                               Left without using A.O and right side with A.O

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