Jump to content

Object Lights


Recommended Posts

Hi Guys,

Since this is my first post on the forum let me introduce myself a bit; my name is Koen Hofmeester, im doing the Bournemouth Digital Effects Master and I started using houdini a couple of months ago. I have a couple years of maya experience, so the switch to houdini wasn't that bad but now im really stuck for the first time :) At the moment im working on a character project where I need the character to emit light. The character (an eel) has a snake like spotted skin where some of the spots in the skin need to emit a blueish light. The best thing would be if I could assign a black and white texture to the character where maybe a shader calculates the light from the white spots in the texture. I don't have a lot of VEX experience so I really don't know where to start. I thought about doing it just in comp using glows but this isn't going to work cause I need the light to lit the environment.

Hope somebody can point me in the right direction!

Thanks!

Cheers Koen

Link to comment
Share on other sites

I would do everything to avoid using Global Illumination. Mantra doesn't have geometry lights - which lets faces to shine as they were area lights. So the only solution is to let geometry emit light in global illumination mode - which is bad since this is going to render very slow.

1. I would try to instance lights on a points if your geometry. Try how dense they should be to mimic lit light. Add point if needed (use point cloud?) Maybe you can even instance area light that roughly match geometry area?

Then you apply something like a VEX Supermaterial with emission control, you match these two (lights instanced on geo and geo emission itself - light shouldn't illuminate its geometry as I think). And you're ready.

2. Also with old odforce.net Point Clouds shaders pack comes a one shader that uses points in PC as a light source. This is another way to go.

3. Little more advance trick would be to use photons. Just emit them from your lightning geometry (from a light behind it) and use stored diffused photons to add its energy to illumination of environment.

4. Alternatively you could find "Honey" exporter on this forum that lets you render in Sunflow from Houdini (only H. commercial 8.1). Perhaps the only advantage of this renderer is an ability to turn any geometry into area light. You could render only one "shining" pass to compose with the rest from mantra. Sunflow lacks proper AA quality and many other things but it render area light crazy fast!

Try!

cheers,

sy.

Edited by SYmek
Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

×
×
  • Create New...