= Bump Mapping =
To get detailed information about how to create a model with a bump map in blender and import it to Orxonox, take a look at [[https://www.youtube.com/watch?v=bck1eU4e8xo|Youtube Blender Tutorial - Normal Mapping]].

To use a bump map in a material, you can create a new material script inheriting from the base bump map script. Replace both texture image files with your own files.

{{{#!cpp
import * from "BumpMap.material"
// Any number of lights, diffuse
material Cube_Lava_Normal : BumpMap_Base
{
    technique
    {
        pass ambient
        {
        }
        // Now do the lighting pass
        // NB we don't do decal texture here because this is repeated per light
        pass perlight
        {
            // Base bump map
            texture_unit normalmap
            {
                texture Cube_Lava_NORM.jpg
                colour_op replace
            }
        }

        // Decal pass
        pass decal
        {
            texture_unit decalmap
            {
                texture Cube_Lava_COLOR.jpg
            }
        }
    }
}
}}}

The base bump map material script is located at `[media_directory]/materials/BumpMapping/BumpMap.material`

To get an idea what bump maps are capable of, start the test level `BumpMap`

== Important Notes ==
=== Lightning === 
Bump Maps only work with lights and not with ambient lights. Take a look at [[wiki:LevelHowTo#Light|Light]] on hot to use lights (directional, point or spotlight).
 
=== Flickering ===
During the implementation of the bump map functionality the problem of flickering flickering occurred.
This could be fixed by inserting the following lines into ever pass.
{{{#!cpp
 depth_write on
 depth_bias 1
}}}
* Ambient Pass: depth_bias 0
* Lightning Pass: depth_bias 1 
* Decal Pass: depth_bias 2

[[Image(Flickering.png, 200px)]]  

== Screenshot ==
{{{#!rbox align=center)
[[Image(bumpMap.2.png, 800px, align=center)]]  
}}}

== Source ==
[[CollapsibleStart(Base Material)]]
{{{#!cpp
// Any number of lights, diffuse
material BumpMap_Base
{
    technique
    {
        // Base ambient pass
        pass ambient
        {
          // base colours, not needed for rendering, but as information
          // to lighting pass categorisation routine
          diffuse 0 0 0

          // need to prevent flickering
          depth_write on
          depth_bias 0

        }
        // Now do the lighting pass
        // NB we don't do decal texture here because this is repeated per light
        pass perlight
        {

            // do this for each light
            iteration once_per_light
            scene_blend add

            // need to prevent flickering
            depth_write on
            depth_bias 1

            // base colours, not needed for rendering, but as information
            // to lighting pass categorisation routine
            ambient 0 0 0

            // Vertex program reference
            vertex_program_ref BumpMapping/BumpMapVP
            {
                param_named_auto lightPosition light_position_object_space 0
                param_named_auto worldViewProj worldviewproj_matrix
            }

            // Fragment program
            fragment_program_ref BumpMapping/BumpMapFP
            {
                param_named_auto lightDiffuse light_diffuse_colour 0
            }

            // texture shadow receiver program
            shadow_receiver_vertex_program_ref BumpMapping/BumpMapVPShadowRcv
            {
                param_named_auto lightPosition light_position_object_space 0
                param_named_auto worldViewProj worldviewproj_matrix
                param_named_auto worldMatrix world_matrix
                param_named_auto texViewProj texture_viewproj_matrix
            }
            // Additive texture shadow receiver program
            shadow_receiver_fragment_program_ref BumpMapping/BumpMapFPShadowRcv
            {
                param_named_auto lightDiffuse light_diffuse_colour 0
            }

            // Vertex program reference
            vertex_program_ref BumpMapping/BumpMapVPSpecular
            {
                param_named_auto lightPosition light_position_object_space 0
                param_named_auto eyePosition camera_position_object_space
                param_named_auto worldViewProj worldviewproj_matrix
            }

            // Fragment program
            fragment_program_ref BumpMapping/BumpMapFPSpecular
            {
                param_named_auto lightDiffuse light_diffuse_colour 0
                param_named_auto lightSpecular light_specular_colour 0
            }


            // Base bump map
            texture_unit normalmap
            {
                texture Cube_Lava_NORM.jpg
                colour_op replace
            }
        }

        // Decal pass
        pass decal
        {
            // base colours, not needed for rendering, but as information
            // to lighting pass categorisation routine
            lighting off

            // need to prevent flickering
            depth_write on
            depth_bias 2

            scene_blend dest_colour zero
            texture_unit decalmap
            {
                texture Cube_Lava_COLOR.jpg
            }
        }
    }
}
}}}
[[CollapsibleEnd]]