# Edit Edit an Image Page: Bump Mapping

You have to log in to edit pages.

To create an image page, simply complete the form below and then hit the 'Save Page' button at the bottom of the form. As you complete the form, remember that one of the main goals of the Math Images Project is to provide explanations of the images on our site at various levels, so that everyone can understand some of the math behind the images. Try to complete the form as fully as possible, but remember that other users will have the opportunity to add more information to your image pages in the future. Also, please note that by contributing to the Math Images Project, you agree to comply to the guidelines as stated in our general disclaimer.

As always, thank you for your contributions! --The Math Images Project

If you need help filling out this page, please consult our Help sections: Want to Contribute and Math Resources.

Note: * Indicates a required field.

Please note: When you are filling in the below explanations, you should feel free to use standard wikitext.

 Image Title*: Upload a Math Image Bump mapping is the process of applying a height map to a lit polygon to give a polygon the perception of depth. When a polygon is rendered using bump mapping, the polygon's surface normals are perturbed based on a height map or a normal map. When the polygon is lit, the perturbed surface normals cause variations in the lighting across the surface which appear as 'bumps'. The algorithm is a simple extension of basic shading models. In a [[Flat Shading|flat shading]] model, the normal of a polygon is constant across the entire surface. In a [[Phong Shading|Phong shading]] model, normals are interpolated across the surface. With bump mapping, normals vary across the surface due to a height map or a normal map. Note that bump mapping is not it's own shading model, and can be used in conjunction with many shading models. As seen from the following illustration, bump mapping does nothing to simulate the distorted geometry of the height maps; it only changes surface normals. Because of this, bump mapping is not capable of simulating self-shadowing. [[Image:SurfaceComparison.png]] ==Demonstration== Instructions: The panel on the left side of the applet represents the height map of the bump map. You can edit this by clicking and dragging. Left clicking will draw a lighten a circle on the height map and right clicking will darken a circle on the height map. You can change how much lightening or darkening is done by using the "Brush Opacity" slider. You can also change the size of the circle with the "Brush Width" slider. On the right side of the applet is the resulting bump mapped quad. You can click and drag this panel to move the light around to see the effect of the bumps from different angles. {{HideThis|1=Interactive Applet|2=}} Algebra Analysis Calculus Dynamic Systems Fractals Geometry Graph Theory Number Theory Polyhedra Topology Other None Algebra Analysis Calculus Dynamic Systems Fractals Geometry Graph Theory Number Theory Polyhedra Topology Other None Algebra Analysis Calculus Dynamic Systems Fractals Geometry Graph Theory Number Theory Polyhedra Topology Other Yes, it is.