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Definition
Bump maps are greyscale images that use the intensity of adjacent pixels to show surface relief. They create the illusion of surface relief by manipulating the surface normals to make the surface appear unsmooth. In Blaze 3D, white areas of a bump map are shown as high and black areas are shown as low.
Overview
Bump maps are an effective method of adding minute detail to an object which would otherwise require a large number of polygons. As Blaze 3D is an online real-time renderer, it is important to keep the polygon count and file size as low as possible. This ensures that the online presentation loads as quickly as possible and does not require intensive processing power keeping user interaction-response time at a minimum. How to Apply a Bump Map Texture to a 3D Model
Create a greyscale image of the texture. As you paint a bump map using shades of grey, note that it is the change in intensity from one pixel to another which determines the amount of surface relief. For example, a black pixel next to a black pixel will have no effect, whereas a black pixel next to a white pixel will maximise the illusion of height. To make a gradual incline, place increasing shades of grey together. Reverse this order of grey for a declining slope.
From this dialogue, it is possible to alter the intensity of the bump map by adjusting the Strength sliding scale. A value of 0 has no effect and a value of 2048 has a maximum effect.
Hints and Tips
Note that bump maps should only be used to create very shallow reliefs. For example, embossed text, light depressions or grooves. If bump maps are over-used this will increase the time taken to render the 3D object and will look inaccurate if used to create large indentations or huge domes etc.
When using a bump map on a surface, it is possible to adjust the amount of effect it has within Blaze 3D Studio using the slider in the Surface Shader Properties window. To get to this dialog box, left click on the surface. You will see the slider can be adjusted and the model is updated in real time. Be wary of using too high a setting as this may give unexpected results when published.
Sample Project: Refer to the Bump Maps tutorial available as part of the Blaze 3D Extras in Blaze 3D Studio. |
