This shader is no longer supported, and scenes using it will not display correctly.
Shader Type: RealTime
Output: RealTime
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This shader is no longer supported, and scenes using it will not display correctly. |
The OGL Shadowmap uses a shadowmap algorithm to reproduce the shadows created by a single spotlight. The shadows are output to a buffer, and then projected onto the objects to which the shader is applied. Because it accurately reproduces any one spotlight’s shadows, this shader is a useful tool for previewing shadows before you render a scene.
Although the shadowmap shader works like other OGL shaders, it is subject to a few restrictions, namely:
• It can only be used with a spotlight.
• It must be applied to a single material shared by all shadow casting, and shadow receiving objects.
• It must be used in its own drawing pass. If you want to see shadows with other surface attributes, you have to blend the shadows with those attributes in a second pass.
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The extent to which you can use this shader depends the graphics card and/or drivers on your machine. |
For a list of graphics cards that are certified for use with Autodesk Softimage, see the Hardware Certification pages of the Partners section at http://www.softimage.com.
Spotlight Parameters
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Light ID |
The OGL numeric ID for the light whose shadows are being rendered. If the correct shadows are not displayed in viewports where Realtime Shaders viewing mode is enabled, an incorrect light ID is the likely culprit. Enable the Show Frustum option (below), and switch from one light ID to the next until you see the frustum and shadows for the desired light. |
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Frustum > Field of View |
Adjusts the frustum of the spotlight specified by the LightID. This is similar to adjusting a spotlight’s Cone Angle. Lower values produce a smaller spot while higher values produce a larger spot. For the shadow map shadows to match rendered shadows, the Frustum value must be the same as the spotlight’s Cone Angle value. It’s a good idea to link these parameters if you are going to modify them frequently. |
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Frustum > Near/Far Plane |
Similar to a camera’s clipping planes, the near and far planes specify the range within which the spotlight is active. |
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Frustum > Show Frustum |
Displays a wireframe of the spotlight’s frustum in any viewports where Realtime Shaders viewing mode is enabled. This is similar to displaying a spotlight’s cone, but the cone’s near and far planes are displayed as well. |
PBuffer Parameters
The PBuffer parameters control the buffer to which the shadowmap is rendered.
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Resolution |
Specifies the resolution of the shadowmap. Higher values give a smoother result but take more time to render and consume more memory. |
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Show PBuffer |
Displays the contents of the PBuffer in a separate window. |
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Output > Capture PBuffer |
When enabled, the content’s of the PBuffer are written to a file. |
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Output > Filename |
If Capture PBuffer is enabled, this is where you specify the filename, path, and extension of the file to which the buffer is written. When you are capturing the PBuffer to a file, it is updated at every frame and the target file is overwritten. Over time, this can consume large amounts of memory and degrade performance. |
The OGL Shadowmap shader should be connected in its own drawing pass. Because it is a draw type shader, you can connect directly to the target material’s realtime input. However, as the shader does not have built-in blending functions, you must connect it to a draw shader (OGLDraw, for example) if you wish to blend the shadows with surface attributes defined in another pass.
Autodesk Softimage v.7.5