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This tutorial will go through the process of adding fog to a forest to create an image like below.

• First, You will need to get an image of some trees or a forest. The image used in this tutorial is from http://www.sxc.hu/ (the photo ID is 1181771_10276977) which is a great and free stock image site. Keep in mind that the image should have some depth to really show of the fog and avoid images with heavy sunlight and bright specular highlighting.

• To start bring the image into photoshop and create a new document. We will be using a few layers so make sure Layers is turned on in the Window menu.

• Duplicate the Background layer by Layer> Duplicate Layer.
• Now add a Gradient map by going to Image > Adjustments > Gradient Map… This step will add some grey tonning to the image.

• In the Gradient Map set the left color to a light grey around (R: 208, G: 208 B: 208). The Right color should be a grey around (R: 90, G: 90 B: 90).

• Change the opacity of the gadient map layer that was just made to 25%.

• Now duplicate the layer and change the blend mode to Screen.
• Switch to Eraser Tool, select a soft brush around 100 pixels and adjust the eraser opacity to about 33%. Go through the image and erase areas which are closer to the camera. Below is the erased layer with 100% opacity and a blue backgound to show what was done for this tutorial.

• To create a a fog layer close to the ground Create A New Layer in the Layer Menu or in the Layer Pallette.
• In the PS tool bar choose a light grey and medium grey for the forgound and backgound colors.

• In the filter menu select Render > Clouds then delete the top 2/3 of the layer with Marquee Tool.

• Change the opacity of the Cloud layer to 33%. You will still see a hard edge but this will be cleaned up in the next step.
• In the Photoshop Tool bar select the Smudge Tool and switch to a soft brush about 100 pixels in size.

• Since we are making a ground fog use the Smudge Tool to push the clouds down and around the trees. Also, push the clouds away from objects closer to the camera. The below image has the cloud layer isolated a bit for demonstration purposes.

• For some added fog effect goto Select > Select All. Then in the Edit menu Copy Merged and Paste the layer so it is on top.
• Then in the Filter > Blur > Gaussian Blur menu set a blur between 4.5 and 5.0 pixels.
• Also, change the layer opacity to 25%.
• We only want the fog blurry so switch to the Eraser Tool like before with a soft brush at 30% opacity and begin erasing the objects closer to the foreground.
• The last step is to add some contrast back to the image that was lost in the fog. Add a Brightness/Contrast Adjustment Layer  with the below settings.

The final image of this tutorial is featured at the top of this page. Thank you for reading and we appreciate all coments here at the 4sidedpolygon.com .

Ambient occlusion is a easy way of faking global illumination which gives 3d images an extra look of realism. This tutorial is a quick overview of how to setup a occlusion shader in Autodesk Maya.

• To get started open Maya and import a model which you would like to work on or create an object that has a few creases and or corners. Ambient Occlusion works on all types of surfaces including polygons, nurbs, and Sub D’s so most anything will work.
• First, open Maya’s render settings by going to Window > Rendering Editors > Render Settings.
• Since the Ambient occlusion is a Mental Ray shader select the Mental Ray renderer which should can be found in the common tab as long as the plugin is enabled.

• Next, turn off the Enable Default Light setting in the bottom of Common tab. As a general rule this option should be turned of when starting to light and render a scene because the default light is only a basic ambient light and will blow out the image since we will be using the ambient channel later in this tutorial.

• Switch to Mental Ray render tab and make sure raytracing is turned ON. Since ambient occlusion doesn’t need to account for refractions and reflections set those values to 1 to speed up the render a bit.

• To start creating the shader open the Hypershade and create a new Lambert material. Now change the Lambert color to white. In the hypershade menu go to Create > Mental Ray Textures > Mib _Amb _Occlusion.
• In the hypershade work area connect the Output Valueof the occlusion texture to the Ambient Color of the Lambert material.

• Now select the Ambient Occlusion Texture and open up the attribute Editor to change the parameters.
• The Samples control the amount of points to be occluded. I set mine to 48 as a standard but if the image is grainy then set the sample value higher. On thing to remember is the more samples the longer the rendering time will be.
• The Spread attribute is the mix between the light and dark values so a values between .6 and .8 are good.
• The Max_Distance is dependent on the scale of the model. The objective is to have a nice contrast in the edges and details so the bigger the distance value the less contrast there will be.

• The last thing to  do is to change the background color to white in the render view. Select the render camera and in the Environment change the color to white.

• The below image was creating with the settings from this tutorial.

• This covers he basic creation of Ambient Occlusion creation in Maya.
• To composite the image, place the image on top of the color layer and lower the opacity and set the blending mode to multiply which is available in most compositing software and photoshop.

Thank you for visiting the 4sidedpolygon.com and comments are always appreciated……….

This tutorial is a breakdown in creating photographic seamless textures that can be used for 2d graphics and 3d texturing. To start off, creating seamless textures from can take any where from a couple of minutes to a few hours depending on the complexity of the pattern and the photo itself is important.

Tips:

• Look for images with even lighting and keep away from photos with a lot of specular highlighting. I make it a habit when taking photos to use natural light and turn off the camera flash or diffuse it some way. A scanner is a good option for things like cloth and paper.
• The larger the area in the image the better. For instance, when I want to make a grass texture I try to capture at least a meter or two because getting a close up will often show to much repetition.

To get started either download the below image which is a lower resolution version from this sites texture library or use one of your own.

• Open photoshop and make a new document at 512*512 pixels at 72 pixels per inch. Seamless textures don’t have to be a square image but it will help with explaining this tutorial.
• Drag and drop the original image into the new document.
• Use edit> transform> scale to scale down the original image which is now on its on layer in the document to something like the below image.

• Now switch to the Crop tool and make sure the tool is set to delete what is outside the document and then select the whole document and crop. This step is important because the filter we will be using will not work properly without cropping.

• The Filter we will be using is called Offset which can be found under Filter> Other> Offset. We will use the filter to cut the image into four pieces and flip those pieces in the horizontal and vertical direction.
• In the filter options set the horizontal and vertical offset to 256. Setting the offset to 256 pixels will put the seam in the center of the image since the original is 512 pixels. Also, the Wrap Around option should be selected.

• With the image processed the image should look like something below.

• The way this works is that if we cover up the center seams so that the center of the image looks fluid then the image will be seamless. This is an easy concept but it does take some time master.
• To get started swith to the Clone Stamp Tool. I am using a soft brush at 45 pixels with the hardness set to 50%. In my opinion using a completly hard brush or completly soft brush leaves artifacts and unwanted blurring but overtime you will probably develop your own tool set.

To use the clone stamp hold the Alt key and left click once. When holding the Alt and left clicking it sets where the clone source will start. Find a good point that looks like a good cover for the center seams and start painting over it. A good tip is to set clone points often and make sure the area being cloned has a large enough sampling area. Below are the areas I cloned from.

• In the below image I used the clone stamp and covered up the seams and the cracks in the tile. This image can almost be considered seamless. To check, use the Offset tool again with the same settings and use the Clone Stamp again to clean up any imperfections you might see in the center seams. Once the image can be offset without seeing center seam you can consider you image a seamless texture.

Thank you for reading and I hope this tutorial has been useful and informative…..