Showing posts with label Tutorials. Show all posts
Showing posts with label Tutorials. Show all posts

Wednesday, June 10, 2009

Specular Highlight Tutorial

Ok, So I am sure everyone knows several ways to accomplish this task. Various tutorials on specular map creation can be found all over the web. The most interesting thing is most of them have different steps. As artists we must remember that there is never a right or wrong way to do something. Only the end result matters. Only with experimention and trial and error will our creations ever look exceptional. My goal with this tutorial was to figure out a way to accomplish this task using Photoshop. In this example I'll show you how I was able to accomplish this task. So lets get started.

1. Desaturate Diffuse

After I have the diffuse texture complete. I flatten the image.
Then I desaturated the image like in the image #1. Desaturate can be found under Image-Adjustments-Desaturate. The result can be seen in image #1.

2. Minimum Filter at 1 pixels

Next I duplicate the layer from above and place it ontop of my desaturated diffuse. Set the blend mode of this layer to Difference. Next, run this layer through the Minimum filter with a value of 1. The filter can be found under Filter-Other-Minimum. The purpose here was to define edges and areas that would appear a bit lighter. I ran mine at 1 pixels but it isn't an exact
science. Feel Free to experiment with your settings. The results
can be seen in image #2.

3. Overlay a third copy of the diffuse.

Last step!! Place an unaltered copy of the colored diffuse over the top of the first two layers. Set the layer blend mode to Linear Dodge (Add). This helps lighten some of the edges and helps with blending. Lower the layer Opacity to 25%. With this step we are coloring the specular so that the highlights from the object matches what would actually be cast under real light conditions. The result can be seen in image #3.

Ambient Occlusion Tutorial

Ok so I am sure everyone knows several ways to accomplish this task. Even in Maya you can bake out an Ambient Occlusion pass. My goal with this tutorial was to figure out a way to accomplish a similar effect using Photoshop. In this example I'll show you how I was able to accomplish this task. So lets get started.

1. Desaturate Diffuse

After I have the diffuse texture complete. I flatten the image.
Then I desaturated the image like in the image to the right. Desaturate can be found under Image-Adjustments-Desaturate.

2. Highpass Filter at 2 pixels

Next I run the image from the step above through a Highpass
filter. The filter can be found under Filter-Other-Highpass.
The purpose here was to define edges and areas that could
appear a bit darker. I ran mine at 2 pixels but it isn't an exact
science. Feel Free to experiment with your settings. The results
can be seen in image #2.

3. Adjust threshold
Almost there! With this step we are still refining the outline/defining the dark areas that should appear shaded. So we make a threshold adjustment in this step. The Threshold adjustment can be found under Image - Adjustments - Threshold. The result can be seen in image #3.

4. Multiple the layer over the diffuse at a 35% opacity
In this last step we are just creating a layer on top of the diffuse and then using our third image with a photoshop blend mode. I set the blend mode to multiply and lowered the opacity to 35% to help fade out the effect and make it blend better. The result can be seen in image #4.