You might also find the TransferFunctionHelper to be useful:

http://yt-project.org/docs/dev/visualizing/volume_rendering.html#transferfun...

On Friday, May 23, 2014, Michael Zingale michael.zingale@stonybrook.edu wrote:

My guess is that you need to play with the alpha values when you add_layers. From the docs, if you don't supply alpha, it is:

"The alpha value height for each Gaussian. If not supplied, it is calculated as the logspace between -2.0 and 0.0"

so it looks like the last value you add will have alpha = 1, i.e. opaque.

On Fri, May 23, 2014 at 10:57 AM, Stephanie Tonnesen <stonnes@gmail.comjavascript:_e(%7B%7D,'cvml','stonnes@gmail.com');

...

wrote:

...

Hi all,

I am trying to make a nice volume rendering, and am having some trouble. My camera commands are: tf = ColorTransferFunction((-29,-24)) tf.add_layers(8,w=0.1,colormap="Hue Sat Value 2") tf.sample_colormap(-26.5,w=0.02,colormap="Hue Sat Value 2") cam = pf.h.camera([0.0,2.,1.8],[0.0,-1.0,-0.2],4.0,512,tf) cam.show()

I will attach the image, also (v11). First, when I use add_layers, can I get yt to print out WHERE the layers are? Second, but related, when I just use add_layers I only see the higher density gas. I have to add sample_colormap to see lower density gas (the blue stuff). Compare v11 to v6 to see what I am talking about.

Thanks!

Stephanie

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-- Michael Zingale Associate Professor

Dept. of Physics & Astronomy • Stony Brook University • Stony Brook, NY 11794-3800 *phone*: 631-632-8225 *e-mail*: Michael.Zingale@stonybrook.edujavascript:_e(%7B%7D,'cvml','Michael.Zingale@stonybrook.edu'); *web*: http://www.astro.sunysb.edu/mzingale

Looks like google turned up an older version of the docs, you are right, the latest yt sets alpha to 1.

On Sat, May 24, 2014 at 4:00 PM, Stephanie Tonnesen stonnes@gmail.comwrote:

Hi Michael and Nathan,

Thanks for the help! Michael, everywhere I have been looking in the documentation it says for alpha: "The alpha value height for each Gaussian. If not supplied, it is set as 1.0 everywhere." ( http://yt-project.org/docs/dev/reference/api/generated/yt.visualization.volu...) Can you send me a link to what you are referring to so I can try and figure out which applies?

Nathan, that is what I get for not scrolling to the bottom of the page! I will play around with this.

-Stephanie

On Fri, May 23, 2014 at 11:09 AM, Michael Zingale < michael.zingale@stonybrook.edu> wrote:

...

My guess is that you need to play with the alpha values when you add_layers. From the docs, if you don't supply alpha, it is:

"The alpha value height for each Gaussian. If not supplied, it is calculated as the logspace between -2.0 and 0.0"

so it looks like the last value you add will have alpha = 1, i.e. opaque.

On Fri, May 23, 2014 at 10:57 AM, Stephanie Tonnesen stonnes@gmail.comwrote:

...

Hi all,

I am trying to make a nice volume rendering, and am having some trouble. My camera commands are: tf = ColorTransferFunction((-29,-24)) tf.add_layers(8,w=0.1,colormap="Hue Sat Value 2") tf.sample_colormap(-26.5,w=0.02,colormap="Hue Sat Value 2") cam = pf.h.camera([0.0,2.,1.8],[0.0,-1.0,-0.2],4.0,512,tf) cam.show()

I will attach the image, also (v11). First, when I use add_layers, can I get yt to print out WHERE the layers are? Second, but related, when I just use add_layers I only see the higher density gas. I have to add sample_colormap to see lower density gas (the blue stuff). Compare v11 to v6 to see what I am talking about.

Thanks!

Stephanie

---

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-- Michael Zingale Associate Professor

Dept. of Physics & Astronomy • Stony Brook University • Stony Brook, NY 11794-3800 *phone*: 631-632-8225 *e-mail*: Michael.Zingale@stonybrook.edu *web*: http://www.astro.sunysb.edu/mzingale

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