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  1. #1

    UV Displacement Baking?

    I saw Matt's post in this thread:

    http://blenderartists.org/forum/show...44#post1202744

    I was trying to follow the steps and bake a displacement map from a higher poly model on the second layer to a low poly model on the first layer.

    Could someone take a look at the .blend file and let me know the steps or settings I missed?

    Thank you.

    Originally Posted by DichotomyMatt View Post
    Thanks to the option which allows baking from selected to Active, you do not need to unwrap the high-poly mesh. Here is the steps:

    1) Make a copy of your object.

    2) Unwrap the copy at a low resolution.

    3) Add a new image to the unwrapped mesh using the UV / Image window.

    4) Make sure the High-poly and Low-poly objects share the exact same location in Blender (having them on separate layers can help. You can work on one layer at a time and then select both layers when you bake.)

    5) Select the High-Poly Object, Shift Select the Low-Poly object. This leaves both selected with the Low-poly being the Active selected object.

    6) In the Render panel, select the Bake tab.

    7) Choose the map you want to Bake (Normal or Displacement).

    8) Choose the "Selected to Active" button.

    9) Click Bake.
    Attached Thumbnails Attached Thumbnails Click image for larger version. 

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    Last edited by harveen; 24-Sep-08 at 21:39.



  2. #2
    Member DichotomyMatt's Avatar
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    You did not miss any steps. The grey scale image that baked is the displacement map. What you may be missing is how displacement maps work when you render. In order for Displacement to work, you need to add more verts to your low poly mesh. That is to say, it either needs subdivided or to have a subsurf modifier added with a high render level. Here is what I get after adding subsurf render level 5 and maxing out the Disp value for your baked texture. (Note: also set both the high and low poly models to Smooth before baking and rendering.)

    Click image for larger version. 

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  3. #3
    Member PapaSmurf's Avatar
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    generally, use the image as a Bump (normal) map, not as a the Displacement map. To get it looking the same if useing a displacement map, you would have to have as many verts as the hi=poly.



  4. #4
    Originally Posted by DichotomyMatt View Post
    What you may be missing is how displacement maps work when you render. In order for Displacement to work, you need to add more verts to your low poly mesh. That is to say, it either needs subdivided or to have a subsurf modifier added with a high render level. Here is what I get after adding subsurf render level 5 and maxing out the Disp value for your baked texture. (Note: also set both the high and low poly models to Smooth before baking and rendering.)
    Thanks for the help. I'm glad I was on the right track.

    I followed your suggestions and Set Smooth both the low poly and high poly before baking. The results were less bumpy that I would have liked, even at max Displacement, so I started over with Set Smooth only on the low poly and left the high poly alone when baking (I used an even higher poly count than my original .blend). Then I set Subsurf 5 to render. That seemed to give a better result.

    My low poly object has 48 faces. Is that too low for a base mesh to bake on a lot of detail? Should I subdivide the base mesh more to start out?

    What is a good resolution for the underlying color texture? In my original blend, I had scaled down the texture, but for these tests I used the full sized 2240x1680 image.


    This time I also baked Normals. Is Tangent the correct setting for baking Normals?

    In the texture settings I added the following. Are these the right settings?

    Color texture (flat texture): Map Image: Camera
    Displacement baked: Map Image: Tangent
    Normal baked: Map Image: Tangent + Normal Map checked

    For the Color texture, Map Input: I selected UV, the same as for the Normal and Displacement maps.

    I set Map To: Displacement to 1.0 and Normal to 2. What is the normal range for these settings? Are these too low or high?


    For these renders, I used both Displacement and Normal maps. I gather from your comments that I usually should just use one or the other.


    I also wanted to see how these would look in the game engine. In the game engine, it looks like the base low-poly mesh with a flat texture. Is there something else I need to do so there will be more texture relief/definition closer to the look of the BI rendered version? Or is this a limitation of the game engine?


    Also, I'm not sure if it's a bug or not, but through all my testing with various options (mostly when I hit P to view in the game engine) I would sometimes lose some of my maps. I had to go back and reload the image maps a few times to get the 3D view and render to work properly again.


    Here's a quick test scene with a group of these baked objects.
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    Last edited by harveen; 25-Sep-08 at 10:11.



  5. #5
    Member GRoss's Avatar
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    That looks really good man!
    TOTAL N00B



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