QUICK TUTORIALS ON COMPOSITING IN PHOTOSHOP
You'll need the following: a regular render of your scene, an Ambient Occlusion render and a Z Depth render.
Blending Ambient Occlusion (Improves Lighting And Image Realism)
Open your regular render and your Ambient Occlusion render. (should normally be black and white since you should render everything with a white or light grey color instead of their usual texture)
Put your Ambient Occlusion image on a layer above your normal render and set its layer's blend mode to Overlay. This will make parts of your image darker in places where lighting doesn't really reach/bounce in from the outside, just like in real-life. You might want to play with your AO layer's opacity if you think the image looks too dark.
Adding Depth of Field Effect (Emphasizes Camera Focus)
I opened my rendered image, duplicated the background layer and called it "Depth of Field".
I loaded the Z depth image in another layer, selected its colors (Select > Color Range > 200) then pressed CTRL+ALT+i to inverse the selection.
I Used that selection as a mask on my Depth of Field layer. (Clicked "Add Layer Mask" while my layer and my color range were selected)
I Used a Gaussian Blur filter on that layer to get a smooth depth of field effect. (range was 5 pixels but you can use whatever you like)
This takes seconds to make as opposed to much longer if you render it in 3D. Also, in 3D it tends to look worse unless you turn the quality all the way up and wait hours for one render. (And if you wanted more or less blur, you'd have to make changes and render again)
Using Color Correction (Improving Colors)
I did some color correction by changing the image's levels in photoshop. (Image > Adjustments > Levels) You can adjust colors this way. I wanted to get a more warm look, so I made things a bit more brown/orange.
Adding a Glow
Make a new layer and click Select > Color Range. From the color range menu, select something white or very bright on your image then click OK. (You should set the fuzziness to about 125, but it depends on how bright your image is, so play around with this and see what looks good)
While having white as your foreground color, press ALT+DELETE to fill your selection with the foreground color.
You should select the brightest color of your image for the glow to be realistic. If you want to make, say, a red circle glow red, you should select the red color in your image and fill the selection with red.
Conclusion
That is how you can make some simple changes to your 3D renders very quickly. These changes can add to the realism or looks of your images and they take less time to make and adjust than if you did them in your 3D application. Don't forget you can also make small details stand out more by using the Unsharp Mask filter on your image.
You can test out different looks this way and make your images more realistic or just nicer. You could make a bright scene look like it's taking place at night (Color Correction), or add glows to a sunny scene. You can blur the background or foreground objects around a model you want to focus on using DOF or make an image look less flat by using an Ambient Occlusion layer.
Hope can be usefullStatistics: Posted by TheArmMaXimuS — 08 Aug 2012, 18:47
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