How to Use Environment Mapping with Direct3D on S10.zetaboards.com
If you are looking for a way to create realistic reflections on your 3D models without using ray tracing, you might want to try environment mapping with Direct3D. Environment mapping is a technique that simulates highly reflective surfaces by applying a special texture map that contains an image of the scene surrounding an object. This way, the object appears to reflect its surroundings, without incurring any of the complex computations involved in ray tracing.
In this article, we will show you how to use environment mapping with Direct3D on S10.zetaboards.com, a free forum hosting service that allows you to create your own online community. S10.zetaboards.com is a subdomain of ZetaBoards, a free software designed for hosting and building online communities with no hidden charges or forum limitations[^4^]. You can use S10.zetaboards.com to create your own forum with advanced features, such as forum customization, support for custom domains, extensive BBcode, and advanced security[^4^].
There are many types of environment mapping in use throughout the graphics industry, but we will focus on two common forms: cubic environment mapping and spherical environment mapping. Cubic environment mapping uses six images arranged as faces of a cube to represent the environment around an object. Spherical environment mapping uses a single image mapped onto a sphere to represent the environment around an object. Both methods have their advantages and disadvantages, depending on the shape and orientation of the object and the environment.
Cubic Environment Mapping
Cubic environment mapping is more suitable for objects that have complex shapes and orientations, such as cars, buildings, or furniture. It provides more accurate reflections than spherical environment mapping, but it also requires more memory and processing power. To use cubic environment mapping with Direct3D on S10.zetaboards.com, you will need to follow these steps:
Create six images that represent the six faces of a cube surrounding your object. You can use any image editing software to create these images, such as Photoshop or GIMP. Make sure that the images have the same size and resolution, and that they match the perspective of your object.
Save the images as DDS files, which are compressed texture files supported by Direct3D. You can use tools such as DirectXTex or DirectXTK to convert your images to DDS files.
Upload the DDS files to your S10.zetaboards.com forum using the file manager feature. You can access the file manager by logging in to your forum's admin panel and clicking on \"File Manager\" under \"Tools\". You can upload up to 50 MB of files per forum[^4^].
Create a cube map texture object in your Direct3D code using the D3DXCreateCubeTextureFromFile function. This function takes a pointer to a Direct3D device object, a file name, and a pointer to a cube map texture object as parameters. You will need to pass the file name of one of your DDS files as the second parameter. The function will automatically load all six DDS files that have the same base name and different extensions (such as _px.dds, _nx.dds, _py.dds, etc.)[^1^].
Set the cube map texture object as the source texture for your object's material using the IDirect3DDevice9::SetTexture function. This function takes a stage number and a pointer to a texture object as parameters. You will need to pass 0 as the stage number and the pointer to your cube map texture object as the second parameter[^1^].
Enable environment mapping for your object's material using the IDirect3DDevice9::SetTextureStageState function. This function takes a stage number, a state type, and a state value as parameters. You will need to pass 0 as the stage number, D3DTSS_COLOROP as the state type, and D3DTOP_ADDSIGNED2X as the state value. This will add twice the signed difference between the texture color and 0.5 to the diffuse color of your material[^1^].
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