Possible to render sparkle on snow?

alison

Hi all,

I am working on an outdoor, night, fantasy Christmas design. The scene is using snow/forest as a backdrop.

Any suggestions for parameters to use on the ground to make it look glittery? Sort of like new snow looks under a full moon?

I can make a bump map or other additional texture file to call if anyone has an idea for what might work. And then of course there are the setting...tried some, still plugging on. So far, no sparkle.

Any suggestions or idea appreciated!

Alison

StratDragon

have you tried using a specular map?
http://docs.daz3d.com/doku.php/artzone/pub/tutorials/poser/poser-maps13

[edit] the info in the link still applies but the photos are no longer hosted on the web so no image examples.

Honestly this is something I would do Post-Render in Photoshop or GIMP (Gimp is free but I own Photoshop)

Toyen

As Strat Dragon said, since DS has no particle system that would simulate snow you will have to achieve this look with maps.
Specular map that highlights the glowing areas would be worth trying : )

Let us know what you come up with! I´d love to see the results : )

jestmart

I the scene is lit to appear as early evening there may not be enough light for specular. Either add a light and set it to specular with a high intensity or fake the glitter effect with an ambient map.

alison

Thanks all!

The scene is a full moon over snow...so I suppose it wouldn't look super sparkly in *reality*, but after a bit of sur-reality. ; )

I'll get back and see what I can do with your suggestions. I own Photoshop too, so I will also give it a try in post.

Thanks again!

Cross22

Just a few notes:
It's hard to get interesting sparkles in just a still image- much more convincing in an animation.
Textures that you apply to an object are typically smoothed due to interpolation and filtering which is not what you see in real life. In Render Settings you can reduce the Pixel Samples and Pixel Filter Width to 1; this will make the high frequency noise in your specular texture stand out more. Unfortunately it will also make the rest of your scene look uglier..

For this reason the sparkles should be added in image space instead of object space- a shader created with Shader Builder/Mixer would be a good option. The easier way is to do this is in Photoshop after rendering though. Here is one recipe:

- Make a duplicate of the document using Image/Duplicate.
- Apply some generous Filter/Gaussian Blur to that duplicate, then turn it into a grayscale image (Image/Mode/Grayscale)

- Switch back to your original document
- Go to Select/Load Selection, then pick the copied Document you just created along with Layer: Gray
- Click on Layer/New Fill Layer/Solid Color.. to create a black layer
- Change that layer's mode to Overlay or Soft Light
- Finally use Filter/Noise/Add Noise.. to add some noise (maybe 40% monochromatic) until it looks right (e.g. right side of the sample image below)