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      <title>Image-Based Lighting Dialog</title>
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      <div class="title_topic5" id="xps10_pagetitle">Image-Based Lighting Dialog</div>
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               <p class="para_td"> <a class="links" href="javascript:void(0)" onclick="top.openFile('visualizing_a_part/vie_vis_visfx_ibl_ov.html');return(false);">Overview</a></p>
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               <p class="para_td">Dialog Options</p>
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               <p class="para_th">Parameter</p>
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               <p class="para_th">Description</p>
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               <p class="para_td"><b class="uiTerm">Use image-based lighting (IBL)</b></p>
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               <p class="para_td">Enables image-based lighting and reflections in high quality images. When enabled, lights set up from the <b class="uiTerm">View</b>&rarr;<b class="uiTerm">Visualization</b>&rarr;<b class="uiTerm">Advanced or Basic Lights</b> dialogs are not used in high quality images. The <b class="uiTerm">IBL</b> image is also used for scene reflections.
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               <p class="para_td"><b class="uiTerm">Image</b></p>
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               <p class="para_td">For best results in both reflections and lighting, we recommend that you choose your own HDRI file (<b class="uiTerm">User Specified Image</b>). You can use images that have already been set from either <b class="uiTerm">View</b>&rarr;<b class="uiTerm">Visualization</b>&rarr;<b class="uiTerm">Visual Effects</b>&rarr;<b class="uiTerm">Background</b> or <b class="uiTerm">View</b>&rarr;<b class="uiTerm">Visualization</b>&rarr;<b class="uiTerm">Showroom Environment</b> for image-based lighting. However, in both of these cases the images are limited to low dynamic range.
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               <p class="para_td"><b class="uiTerm">Image</b></p>
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               <p class="para_td">Specifies an image file to be used for image-based lighting. For best results, use high dynamic range images (HDR and EXR formats).</p>
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                           <p class="para_note_body">Images with resolutions less than 1024 x 1024 are not recommended. Low resolution images result in reflection aliasing.</p>
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               <p class="para_td"><b class="uiTerm">Lighting Intensity</b></p>
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               <p class="para_td">Sets the intensity of the lighting which depends on the image and scene. Start with a full <b class="uiTerm">Lighting Intensity</b> of 1.0. This should work for most cases. If the results are too bright or too dark, reduce or increase the intensity slightly.
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            <td bgcolor="#f4f4f4" colspan="1" rowspan="1" valign="top"><a name="lighting_accuracy"></a><p class="para_td"><b class="uiTerm">Lighting and Shadow Accuracy</b></p>
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               <p class="para_td">The value represents the number of samples used to evaluate the <b class="uiTerm">IBL</b> image to determine the number of light sources and shadows it contains. The higher the value, the more accurate the lighting and shadows relative to the image and the longer it will take to render a high quality image. Experiment to obtain results that you like. The setting you need depends on the image, the scene, and the shadow type you have chosen. Start with a low setting to generate a quick preview of your final high quality image and increase the value as needed.  If the image you're using represents relatively uniform lighting, a lower <b class="uiTerm">Lighting and Shadow Accuracy</b> setting might be required. If the image contains many small, bright lighting areas, a higher value will result in more light sources detected in the high quality image generated.
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               <p class="para_td"><b class="uiTerm">Lighting Color Saturation</b></p>
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               <p class="para_td">Increases or decreases the lighting's degree of coloration in the scene. For example, to make the sky color in an outdoor image more intense, increase the degree of coloration. If the lighting from the image appears too blue in the high quality images you generate, reduce the degree of coloration.</p>
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                           <p class="para_note_body">This option affects only the lighting color, not the reflection color.</p>
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               <p class="para_td"><b class="uiTerm">Shadows</b></p>
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               <p class="para_td">Select one of the following shadow types:</p>
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                        <p class="para_th">Shadow Type</p>
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                        <p class="para_td"><b class="uiTerm">Disabled</b></p>
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                        <p class="para_td">Generates a quick preview of your final high quality image when shadows are not needed in your scene.</p>
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                        <p class="para_td"><b class="uiTerm">Approximate Mapped</b></p>
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                        <p class="para_td">By default, <b class="uiTerm">Approximate Mapped</b> shadows are soft-edged. The software uses a shadow depth mapping algorithm to generate the shadows. For many cases, this option produces good results.
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                        <p class="para_td"><b class="uiTerm">Precise Raytraced</b></p>
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                        <p class="para_td">By default, <b class="uiTerm">Precise Raytraced</b> shadows are hard-edged. The software uses a raytracing algorithm to generate the shadows so the results are more accurate than with <b class="uiTerm">Approximate Mapped</b>. Choose this setting when you require accurate or hard-edged shadows or when <b class="uiTerm">Approximate Mapped</b> shadows don't produce the desired results. This option increases rendering time for the same <b class="uiTerm">Lighting and Shadow Accuracy</b> setting relative to when you use <b class="uiTerm">Approximate Mapped</b> shadows.
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                        <p class="para_td"><b class="uiTerm">Raytraced Transparent</b></p>
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                        <p class="para_td">Acts and looks the same as <b class="uiTerm">Precise Raytraced</b> except it also produces shadows for transparent objects in your scene. It matches the shadow color to the color of the corresponding transparent object.
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               <p class="para_td"><b class="uiTerm">Softness Tuning</b></p>
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               <p class="para_td">Adds softness to shadows and depends on the type of shadow generation method you have chosen. You may not need this setting at all.</p>
               <p class="para_td"><b class="uiTerm">Approximate Mapped</b> shadows are soft-edged by default. Use this option if you want to exaggerate the softness you already have with <b class="uiTerm">Approximate Mapped</b> shadows.
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               <p class="para_td">For <b class="uiTerm">Approximate Mapped</b> shadows, if you set the <b class="uiTerm">Softness Tuning</b> option too high, your table or floor plane might become dark with shadow artifacts.
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               <p class="para_td"><b class="uiTerm">Precise Raytraced</b> shadows are hard-edged by default. To make them soft, increase the <b class="uiTerm">Softness Tuning</b> value, which will &quot;jitter&quot; the shadows and add &quot;noise&quot; to them. Jittering adds additional shadows at slightly offset locations. The &quot;noise&quot; is dots that make the jittered shadows appear to be one soft-edged shadow.
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               <p class="para_td">If you decide to use this option, experimentation will also be required to get the results you like.</p>
               <p class="para_td">Increasing <b class="uiTerm">Softness Tuning</b> for <b class="uiTerm">Precise Raytraced</b> shadows is not recommended for relatively small parts or for close-up views of large parts. In these cases, the &quot;noise&quot; dots can be too big and will look like artifacts rather than shadow softness.
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            <td bgcolor="#f4f4f4" colspan="1" rowspan="1" valign="top"><a name="img_up_vec_rot_ang"></a><p class="para_td"><b class="uiTerm">Image Up Vector and Rotation Angle</b></p>
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               <p class="para_td">To calculate the lighting and reflections from a specified <b class="uiTerm">IBL</b> image, the image is &quot;mapped&quot; to a sphere around the part extents. By default, this mapping uses the part's absolute +Z axis as the relative &quot;up&quot; direction. This lighting behavior is similar to the <b class="uiTerm">Fixed to Part</b> Position setting of <b class="uiTerm">View</b>&rarr;<b class="uiTerm">Visualization</b>&rarr;<b class="uiTerm">Advanced Lights</b>. Use the <b class="uiTerm">Image Up Vector</b> to define the orientation of the mapping sphere and use the <b class="uiTerm">Image Rotation Angle</b> to set a rotation angle in degrees that the image will be rotated about the up vector.
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               <p class="para_td">These options are useful in re-orienting lighting and reflections, particularly with &quot;photography studio&quot; types of images. Using these options is like moving the lights around in a real-world studio during a photo shoot.</p>
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