Glare Shader


#1

Hi, I’m afraid I’m a newbie at all of this so you will have to bare with me.

After reading some great threads on here, I saw that you need to use a Glare Shader (which is hidden) to make a window glow, basically.

Then I see that you have to open lume.mi. Go down to the gui_Glare section a little way down. Once you get there you will see “hidden” a few lines after this. Well on all the posts I have read it says to delete this and then delete the comma after “-tag” on the line above. Then save the file.

Open up max set the renderer to Mental ray and click on the Renderer tab in the Render Scene box go down to camera shaders above half-way down and click on Output and then when the box opens Glare (lume) should appear there, but it doesn’t.

Am I missing something, I have only been using Max for about 2 weeks, so you will have to excuse my basic knowledge, do you have to leave the " ", when you delete hidden or something.

Thanks in advance.


#2

if it was:
“-tag”,
“hidden”

it should be:
“-tag”

and a little tip to avoid crashes:
if you want to test streaks first choose the image otherwise it would kill max.


#3

I would love to see this shader viewable real-time in the viewport with nVidia’s new cards since it is now part of their real-time feature list.


#4

instead of using glare, just add an effect, blur, then blur by luminence. you get the same ish effect, plus its easy to set up, and quick to work.


#5

There’s also an extra script that’s on the 3dsmax CD’s that does this as well.

Jeff


#6

I digged into it and there are some nice features both for composition as a seperate pass and for streaks

what I couldn`t do yet is to change the size of the streaks, if you find the solution post here.


#7

Could someone recomend me a Maya documantation or XSI about the glare shader?

I can’t find anything about max :surprised


#8

What’s wrong? Can’t make it work :hmm:


#9

change the quality to atleast 3.


#10

I think documentation is included if you download the demo of Lumetools Collection 1.

Here


#11

That’s verry strange Jeff, only way to work is with quality in 3. Tnks!

I think that’s why this shader is hidden. :slight_smile:

Do you know the restriction to the Spread parameter? I just can render the scene with it default number.

Tnks pixero, I will take a look!


#12

Hi!

I have a problem with The glare shader: it doesn"t work with mitchell and lanczos filters
in max.(Some edges has strange colors )


#13

You usually won’t notice much difference, but both the blur effect and the bloom script are not similar to the glare shader. Glare uses a higher luminance range to calculate the glows/glares while the blur effect and bloom script use the standard 0-255 RGB space.

This can be seen when you have an super-bright object; this will always be displayed as pure white (255,255,255). The problem is that the range ends at pure white so there is no difference between super-bright or bright: it’s all white to your program. Higher range spaces can overcome this problem by storing colour information beyond 255 and below 0.
What the glare shader does is it takes that colour information beyond the 255 range and scales that down to make the glow.

Example, say you have a yellow object (R:125,G:125,B:62) and the object starts to get brighter and brighter (say a white light starts to shine on it).

  • With a low range colour space the RGB levels first go to (R:255,G:255,B:125), here they get ‘stuck’. As the object gets brighter the levels go to (R:255,G:255,B:255), the object now appears to be pure white. When a glow is applied based on this range you would get a white glow around the object. This is far from realistic as the glow is not the scaled down bright yellow colour.

  • With a high range colour space the RGB levels first go to (R:255,G:255,B:125) (compared to low range RBG), here they can continue on. As the object gets brighter the levels go to, say, (R:1000,G:1000,B:500), the object still appears to be pure white. But when a glow is applied based on this range you could get a yellowish glow around the white object. This is the most realistic of the two.

    Of course the appearance of a coloured glow depends on the brightness of the object and when the objects start to ‘glow’.

Another advantage of the glare shader is having only the brightest of brightest of object emitting a glow. With the blur or glow effect all saturated parts of the image will glow. With the glare shader some white parts might glow while other white parts might not.

For post glows, like in Photoshop, this is also the case. The glares/glows can be much more realistic if you use HDR or OpenEXR images.

Super-bright objects only look that bright in photographs because of the glow around them. If the camera would have a perfect lens then the object would appear to be just as bright as a regular bright object on the same photograph.
The glow comes from internal reflections inside the camera lens. In the lens the light loses a lot of its energy because of the internal reflections, this is why you can sometimes see the base colour of an object that appears to be pure white.
Glows can also be caused by light that passes through the film, hits the backplate and goes back into the film again (halation). But that only happens with IR film or film that saw dinosaurs walk as modern regular film has a special layer to prevent this.

The internal lens reflections have several different causes. The geometric shapes seen in lens flare are caused by the diaphragm, so are the streaks/spikes (there are twice as much streaks as diaphragm blades if I’m not mistaken). The ghosts are caused by the different lenses inside the camera lens.
Dirt and scratches on the lens can also cause light scattering. This always happens with lens imperfections but it only gets noticable with very bright light.

The same goes for your eye really, it also has a non-perfect lens.

Pff, enough technical stuff for one day, time for beer! :smiley:

Hope this helps!

  • Rens

#14

Cool! Thanks for the detailed breakdown Rens! Excellent resource that I can start pointing people to (just like I do for your detailed glow explanation). I know that took a bit of time to write/research…so just wanted to say thanks. :thumbsup:


#15

You’re welcome! And thank you for your MR research. :thumbsup:


#16

I read this quite a few times but for me it also works with lower quality settings. It renders faster and i dont see much difference.


#17

Yeah, the “spread” is what controls the size of the glare (naturally), so a setting of 2 on the quality works fine (and renders fast)…what can I say…this is an old thread and I was just posting how I made it work at that time. :hmm:


#18

How so? I’ve tried a wide range of ‘spread’ values with the glare shader on a quality setting of ‘2’, and I’m seeing no effect.
Are you two doing something else with your scene that would affect this?


#19

Hello. Can the specific brightness that the glare shader affects be set? I rendered an interior scene, and the only “bright white” is from the windows. But I still get glow all over the scene, even on the dark wood floor.

Thanks


#20

I dont think the spread value really controlls the size of the glare …more how sensitive it reacts to bright areas… i mean if you abuse the spread value you can make dark objects glare. I forgot where i found this information tho.
Mimike since the glare shader is not limited to default rgb values you can lower the spread value and make your window over bright then it will be the only object glowing.

Edit: I found this : http://www.lume.com/manual/Contents.html very usefull :scream: btw has anyone ever managed to get these streaks to work ?? they dont seem to work for me :shrug: