Results 1 to 8 of 8

Thread: blending reflections question

  1. #1
    Super Member omichon's Avatar
    Join Date
    Jul 2003
    Location
    Bordeaux, FR
    Posts
    707

    blending reflections question

    I have a scene with a reflecting object laying on a large white ground, that produce no exciting raytraced reflections.
    So I have put some env map on it but I have to define the reflection to sperical map only to see it.
    The problem is that I need to get some of the raytracing reflections at the contact point with the ground and in the inner corners of the object.
    So the question is :
    Is there a way to add some raytracing reflections over a spherical map reflection layer limited by an occlusion mask ?
    Thanks for any node suggestion.

  2. #2
    Super Member omichon's Avatar
    Join Date
    Jul 2003
    Location
    Bordeaux, FR
    Posts
    707
    Well, I put two Reflections shaders into a Mixer, with opacity defined by an Ambient_Occlusion (thanks for it, Denis ) and it seems to do the job, basically.

  3. #3
    Triglycerous Gluteous Dave Jerrard's Avatar
    Join Date
    Apr 2005
    Location
    Burbank
    Posts
    1,061
    Have you tried using Ray Tracing and Spherical Map in the reflections mode? This will ray trace everything except the backdrop, which will be replaced by the spherical image you give it.


    He Who Used This A Lot For Doing Metals.
    Last edited by Dave Jerrard; 02-26-2007 at 01:18 AM. Reason: This is more fun than should be allowed.
    - Any typos are the result of a creative, yet rebellious keyboard.

    ASUS KGPE-D16 MB
    2 AMD Opteron 6272 CPUs
    32GB Kingston KVR1333D3D4R9S RAM
    EVGA|01G-P3-1556-KR GTX550Ti video card

  4. #4
    Super Member omichon's Avatar
    Join Date
    Jul 2003
    Location
    Bordeaux, FR
    Posts
    707
    Thanks for the suggestion Dave.
    The problem in this case, is that the ground polygon is so huge that when looking from above, the env map is never seen in the reflections (except on the top of the object). The idea would be to have the ground unseen by rays, but in this case I miss the contact reflections between the object and the ground.
    I tried to figure out a workaround by rendering different layers, but it's not that easy to comp.
    I also tried to set the ground unseen by rays with an additionnal smaller ground unseen by camera but it's not yet satisfying.
    I don't know if it is possible to define a max distance for the rays used in the reflections with the node editor, but it's my last hope

  5. #5
    Member
    Join Date
    May 2006
    Location
    France
    Posts
    3,925
    The Raytrace node is not limited internally, but you
    can input the Ray Length in A in a Logic node, the max distance
    in B select "Lower..." and output the result (true = 1) in a Mixer opacity,
    to exclude such far reflections.

    Denis.
    Last edited by dpont; 02-26-2007 at 03:58 AM.

  6. #6
    Super Member omichon's Avatar
    Join Date
    Jul 2003
    Location
    Bordeaux, FR
    Posts
    707
    Quote Originally Posted by dpont
    The Raytrace node is not limited internally, but you
    can input the Ray Length in A in a Logic node, the max distance
    in B select "Lower..." and output the result (true = 1) in a Mixer opacity,
    to exclude such far reflections.

    Denis.
    Well, the raytrace node is not limited, but my knowledge about nodes is very limited
    Anyway, I see the idea. I will play with it.
    Thanks, Denis, for the suggestion

    BTW, do you think it would be possible to add some fall off on the result, because I am afraid that a ON/OFF flag on opacity could produce some wacky results.

  7. #7
    Member
    Join Date
    May 2006
    Location
    France
    Posts
    3,925
    You can do a falloff effect with a Gradient Node set the
    Length in the Gradient input, in the Gradient panel set a
    value of 1.0 (white) for an input (Length) of 0.0 and a
    value of 0.0 (black) for an input of max length.

    Denis.

  8. #8
    Super Member omichon's Avatar
    Join Date
    Jul 2003
    Location
    Bordeaux, FR
    Posts
    707
    Thanks again Denis, I will test it.

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •