Difference between revisions of "User:Wfpokorny"

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m (Deleted lathe and prism updates after Jim rolled them into the actual documentation.)
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* the above [[Reference:Prism|prism]] additions have been added with a few minor changes. --[[User:Jholsenback|jholsenback]]
 
* the above [[Reference:Prism|prism]] additions have been added with a few minor changes. --[[User:Jholsenback|jholsenback]]
 
<p></p>
 
<p></p>
 +
 +
<p></p>
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* Spindle Torus [[Reference:Torus|torus]] text here to provide me a template for other 3.7.1 updates. --[[User:Wfpokorny|wfpokorny]]
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<p></p>
 +
 +
 +
===Spindle Torus===
 +
<p>{{New.3.7.1}} A torus with a minor radius greater than the major radius
 +
(aka <em>spindle torus</em>) will self-intersect in a spindle-shaped region.
 +
The behaviour with respect to the spindle can be controlled by specifying
 +
either of the <code>difference</code>, <code>intersection</code>,
 +
<code>merge</code> or <code>union</code> keywords, which act similar to the
 +
corresponding CSG operations:</p>
 +
<ul>
 +
<li>Using the <code>difference</code> keyword, the self-intersecting portion
 +
is cut away from the torus, so that the spindle volume is considered
 +
<em>outside</em> the primitive; the spindle surface is visible (provided you
 +
cut open the torus, or make it semi-transparent).</li>
 +
<li>Using the <code>intersection</code> keyword, the resulting shape consists
 +
of <em>only</em> the self-intersecting portion, so that only the spindle volume
 +
is considered inside the primitive, and only the spindle surface is visible.</li>
 +
<li>Using the <code>merge</code> keyword, the surface within the self-intersecting
 +
portion is hidden, so that the spindle surface is <em>not</em> visible; the
 +
spindle volume is considered inside the primitive.</li>
 +
<li>Using the <code>union</code> keyword, the entire torus surface remains
 +
visible and the spindle volume is considered inside the primitive (this is
 +
the default).</li>
 +
</ul>
 +
<p>In a non-spindle torus, the <code>intersection</code> keyword will cause a
 +
"possible parse error" warning and make the torus invisible, while the other
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spindle mode keywords will have no effect whatsoever.</p>
 +
<p class="Note"><strong>Note:</strong> The <code>difference</code> spindle mode
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does <em>not</em> affect the behaviour with respect to the
 +
<code>[[Reference:Interior_Texture|interior_texture]]</code> keyword. An
 +
<code>interior_texture</code> will always be applied to the side of the spindle
 +
surface facing the spindle volume.</p>
 +
 +
<table class="centered" width="420px" cellpadding="0" cellspacing="10">
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<tr>
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  <td>[[Image:SpindleTorusDifference.png|center|200px<!--centered--->]]</td>
 +
  <td>[[Image:SpindleTorusIntersection.png|center|200px<!--centered--->]]</td>
 +
  <td>[[Image:SpindleTorusMerge.png|center|200px<!--centered--->]]</td>
 +
  <td>[[Image:SpindleTorusUnion.png|center|200px<!--centered--->]]</td>
 +
</tr>
 +
<tr>
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  <td colspan="4"><p class="caption">cutaway view of spindle torus using the <code>difference</code>, <code>intersection</code>, <code>merge</code> and <code>union</code> mode, respectively</p></td>
 +
</tr>
 +
</table>
 +
 +
{{#indexentry:sturm, torus}}
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{{#indexentry:keyword, sturm}}
 +
 +
===Sturm===
 +
<p>Calculations for all higher order polynomials must be very accurate. If the
 +
torus renders improperly you may add the keyword <code>sturm</code> to use
 +
POV-Ray's slower-yet-more-accurate Sturmian root solver.</p>

Revision as of 15:02, 30 May 2016

  • the above prism additions have been added with a few minor changes. --jholsenback

  • Spindle Torus torus text here to provide me a template for other 3.7.1 updates. --wfpokorny


Spindle Torus

Template:New.3.7.1 A torus with a minor radius greater than the major radius (aka spindle torus) will self-intersect in a spindle-shaped region. The behaviour with respect to the spindle can be controlled by specifying either of the difference, intersection, merge or union keywords, which act similar to the corresponding CSG operations:

  • Using the difference keyword, the self-intersecting portion is cut away from the torus, so that the spindle volume is considered outside the primitive; the spindle surface is visible (provided you cut open the torus, or make it semi-transparent).
  • Using the intersection keyword, the resulting shape consists of only the self-intersecting portion, so that only the spindle volume is considered inside the primitive, and only the spindle surface is visible.
  • Using the merge keyword, the surface within the self-intersecting portion is hidden, so that the spindle surface is not visible; the spindle volume is considered inside the primitive.
  • Using the union keyword, the entire torus surface remains visible and the spindle volume is considered inside the primitive (this is the default).

In a non-spindle torus, the intersection keyword will cause a "possible parse error" warning and make the torus invisible, while the other spindle mode keywords will have no effect whatsoever.

Note: The difference spindle mode does not affect the behaviour with respect to the interior_texture keyword. An interior_texture will always be applied to the side of the spindle surface facing the spindle volume.

SpindleTorusDifference.png
SpindleTorusIntersection.png
SpindleTorusMerge.png
SpindleTorusUnion.png

cutaway view of spindle torus using the difference, intersection, merge and union mode, respectively

Sturm

Calculations for all higher order polynomials must be very accurate. If the torus renders improperly you may add the keyword sturm to use POV-Ray's slower-yet-more-accurate Sturmian root solver.

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