<div dir="auto">Holger, this appears to be nearly what I wanted in my VariationalPhysicsModel, except I made my scale based on random variations within a range.   This was so I could animate the equation:</div><div dir="auto"><br></div><div dir="auto">r = A + B * cos(C * phi) * cos(D * theta)</div><div dir="auto"><br></div><div dir="auto">A, B, C and D are all scaled independently according to random values, with limits.</div><div dir="auto"><br></div><div dir="auto">If you could show a demo (does the one below have it?) with randomized scale over time, great!</div><div><br><div class="gmail_quote gmail_quote_container"><div dir="ltr" class="gmail_attr">On Wed, Oct 29, 2025 at 12:42 PM Holger Seelig via x3d-public <<a href="mailto:x3d-public@web3d.org">x3d-public@web3d.org</a>> wrote:<br></div><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div style="line-break:after-white-space">The new latest of X_ITE comes now with two new fields for ParticleSystem. That are scaleKey and scale fields. They work much like colorKey and color fields.<div><br></div><div><font color="#000000">A user asks me for the ability to scale the particles during the time, basically to make the particles grow from its creation time and then shrink.</font><br><div><br></div><div>Other 3D engines like Unity have this already for a long time.</div><div><br></div><div>With the two new fields it is possible to have a curve and finely adjust the size over the time.</div><div><br></div><div>New fields will look like this:</div><div><br></div><div>inputOutput MFFloat scaleKey [ ]</div><div>inputOutput SFNode scale NULL  [Coordinate]</div><div><br></div><div>It will work with all geometry types a ParticleSystem can have, even GEOMETRY.</div><div><br></div><div><div style="color:rgb(0,0,0)"><font color="#000000"><span>I prepared a very simple example that shows the capabilities of these new fields:</span></font></div><div style="color:rgb(0,0,0)"><a href="https://create3000.github.io/x_ite/playground/?url=https://create3000.github.io/Library/Tests/Components/ParticleSystems/Scales.x3d" target="_blank">https://create3000.github.io/x_ite/playground/?url=https://create3000.github.io/Library/Tests/Components/ParticleSystems/Scales.x3d</a><font color="#000000"></font></div><br></div><div>Best regards,</div><div>Holger</div><div><br></div></div><div>
<div dir="auto" style="color:rgb(0,0,0);letter-spacing:normal;text-align:start;text-indent:0px;text-transform:none;white-space:normal;word-spacing:0px;text-decoration:none;line-break:after-white-space"><div dir="auto" style="color:rgb(0,0,0);letter-spacing:normal;text-align:start;text-indent:0px;text-transform:none;white-space:normal;word-spacing:0px;text-decoration:none;line-break:after-white-space"><div dir="auto" style="color:rgb(0,0,0);letter-spacing:normal;text-align:start;text-indent:0px;text-transform:none;white-space:normal;word-spacing:0px;text-decoration:none;line-break:after-white-space"><div dir="auto" style="color:rgb(0,0,0);letter-spacing:normal;text-align:start;text-indent:0px;text-transform:none;white-space:normal;word-spacing:0px;text-decoration:none;line-break:after-white-space"><div dir="auto" style="color:rgb(0,0,0);letter-spacing:normal;text-align:start;text-indent:0px;text-transform:none;white-space:normal;word-spacing:0px;text-decoration:none;line-break:after-white-space"><div dir="auto" style="color:rgb(0,0,0);letter-spacing:normal;text-align:start;text-indent:0px;text-transform:none;white-space:normal;word-spacing:0px;text-decoration:none;line-break:after-white-space"><div dir="auto" style="color:rgb(0,0,0);letter-spacing:normal;text-align:start;text-indent:0px;text-transform:none;white-space:normal;word-spacing:0px;text-decoration:none;line-break:after-white-space"><div dir="auto" style="color:rgb(0,0,0);letter-spacing:normal;text-align:start;text-indent:0px;text-transform:none;white-space:normal;word-spacing:0px;text-decoration:none;line-break:after-white-space"><div dir="auto" style="color:rgb(0,0,0);letter-spacing:normal;text-align:start;text-indent:0px;text-transform:none;white-space:normal;word-spacing:0px;text-decoration:none;line-break:after-white-space"><div dir="auto" style="color:rgb(0,0,0);letter-spacing:normal;text-align:start;text-indent:0px;text-transform:none;white-space:normal;word-spacing:0px;text-decoration:none;line-break:after-white-space"><div dir="auto" style="text-align:start;text-indent:0px;line-break:after-white-space"><div style="color:rgb(0,0,0);letter-spacing:normal;text-transform:none;white-space:normal;word-spacing:0px;text-decoration:none">—</div><div style="color:rgb(0,0,0);letter-spacing:normal;text-transform:none;white-space:normal;word-spacing:0px;text-decoration:none">Holger Seelig<br><a href="mailto:holger.seelig@yahoo.de" target="_blank">holger.seelig@yahoo.de</a><br><br></div></div></div></div></div></div></div></div></div></div></div></div>
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