render as points, really only points

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hello forum,
using H14, i cant get mantra to render points only. i have millions of advected particles and wanna render it “krakatoa”-style, which means really as points only - and no sprites, circles or spheres. of course i googled, but all posts tell me to set the geo/render/geometry to “render as points”, but still i am getting sprites (i am rendering extremly close, my cam is almost inside the pointcloud). tried micropolygon, raytrace, pbr.
attached a screenshot which i hope makes clear what i mean. or am i missing somehting obvious? noob bug?
thanks in advance.
fuat

Attachments:
RenderNotAsSprites.jpg (1.4 MB)

Fuat Yüksel
FX Supervisor | RISE Visual Effects Studios
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Hi ,

add a pop wrangle with @pscale = 0.001 and set the pop geometry node to render as circles

Rob
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I see a terminology conflict here, because what you're really after is a ‘render each point as a single pixel’ mode.

You could go fancy and calculate the pscale according to distance to camera. That way you ensure all point to be equal in size in the camera plane and probably use fewer samples.

Simply apply a ‘uvtexture’ node on your points, use camera space and choose your cam. The resulting uv.z value is your distance to cam. Use that value and a constant to set the point size.

Attribute wrangle example:
@pscale = @uv.z * 0.01; // or use ch(“scale”) and have it create a slider

Have fun,
Andy
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points still have scale in space so the closer they are to camera the bigger they get, you can compensate by scaling them according to distance.
here's an example:

Attachments:
pointScale.hip (1.3 MB)
pointScale.mantra1.0002.jpg (1.2 MB)
pointScale.mantra1.0001.jpg (1.2 MB)

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circusmonkey
Hi ,

add a pop wrangle with @pscale = 0.001 and set the pop geometry node to render as circles

Rob

thank you very much, Rob. seems to work.
just because i really want to understand whats going on: what is the difference between this approach and the Pointscale parameter in the Geo/Render tab? i tried that yesterday, using a value of 0.01 (with a prior pscale of 0.01), which gives a me not the desired result (my screenshot from yesterday). isn´t that a kind of a post-multiplier on the pscale attrib?
thanks again.
fuat
Edited by - March 17, 2015 07:27:02
Fuat Yüksel
FX Supervisor | RISE Visual Effects Studios
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thank you very much, guys.
this software and this forum make me happy.
Fuat Yüksel
FX Supervisor | RISE Visual Effects Studios
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fuat
circusmonkey
Hi ,

add a pop wrangle with @pscale = 0.001 and set the pop geometry node to render as circles

Rob

thank you very much, Rob. seems to work fine. great.
just because i really want to understand whats going on: what is the difference between this approach and the Pointscale parameter in the Geo/Render tab? i tried that yesterday, using a value of 0.01 (with a prior pscale of 0.01), which gives a me not the desired result (my screenshot from yesterday). isn´t that a kind of a post-multiplier on the pscale attrib?
thanks again.
fuat


No problem. The point scale is a multiplier on the pscale attribute . The render only as points tab will make sure only the points get rendered , every thing else is discarded. If you fly inside your cloud with a camera of course your points get bigger as they are closer to camera. At the end of the day its alll about what the end goal is , if its to render millions of points, there's some great threads around , both here and odd force, most I ever rendered was 60 million, years ago, I bet with 14 and enough ram it could be a far larger amount now. :roll:

Rob
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