How can i make a knee brace

[Anonymous]

Hi there
Does anybody have any suggestions for making the decoration (marked with red circle) of the knee brace in the photo?
Thank you

[Karl Ottenstein]

I would use a combination of a simple object and two texture maps (materials). The following sounds complicated, but only takes a few minutes once you've done it a time or two.

If the decorative brace does not have to be at absolutely perfect scale, then do the following (if it has to be to scale, then drawing is more obvious):

1. straighten your photo in PS using the freeform transform so that you are looking 'square on' at the side elevation. Make sure your proportions are correct. Crop to show just the brace (perhaps a bit more).

2. For the texture, touch up the shading as needed. (Photos invariably have shadows and glare that are inappropriate.) If you want a bump map, paint that in an alpha chanel. Etc.

3. In AC., place the revised image with the Figure Tool, and scale / resize it as needed to match the physical dimensions as closely as you can (do not distort it or the material will not map 1 to 1 later).

4. Trace a fill over the image of the brace. Zoom in as needed.

5. With the slab tool set to the depth of the brace, magic want the fill. You now have a brace-like shape that is, sadly, flat on the ground. We need to get it rotated vertically and apply textures.

6. The trick is to apply and align textures NOW, because we will then save the slab as a GDL object in order to have it rotated properly ... and once rotated, the only way to adjust textures is in GDL code. We want to do this visually without any coding.

7. Create a new material for the brace 'face', and bring in your adjusted image as the texture, being sure to set the size correctly. In your slab settings, make this the material for the slab top. Select the slab-brace and view it in the OpenGL 3D window. Using the Align 3D Texture command, set the origin and alignment as needed to make your image fit exactly onto your slab-brace. Now, via textures, you have the scroll detail without having had to carve it! Do a similar thing to create and apply a texture for the slab edges.

[Tip here - the default origin of the texture is the lower left, so building your brace-slab as a mirror image of what is shown in your photo, so that there is a hotspot at the lower left, makes texture alignment easier.]

8. When the slab-brace looks right, except for its orientation, then select only it, view it in 3D, "side view", drag the camera in the circle to be at the very top (looking at the top edge of your slab-brace: the view that would appear in plan), and from the File | GDL Objects menu, select Save 3D Model As ... then select the chair icon (object), and save, preferably to a loaded project library folder so you can find it later, but AC will load it wherever you might save it to. By viewing in the desired plan view before saving, the rotation is taken care of for you during the save process and the saved object will be standing up when you place it! No coding needed.

9. The object (chair) tool is now pre-set to your saved object. Place it, and drag it vertically and snap into place in the 3D window (or section)

The brace will look pretty good in renderings. It will look OK in sections/etc. If you have to have it look better in line drawings (elevations) when you have fills turned on, you could define a fill pattern for the brace material that displays lines similar to the scrolling seen in your photo.


This is a too-condensed version of part of a class I teach called "The Object Making Everyone Should Know"...

Karl

[Djordje · Accepted solution]

"teOS Mat" wrote:
Does anybody have any suggestions for making the decoration (marked with red circle) of the knee brace in the photo?/quote]

If you do know all the dimensions of it, including the radii of the volutes, you might try modeling it ... let's say ArchiForma? Not that is it very easy, in any software! Karl's solution is good if you need it only for rendering, but if you also have to document it, then modeling is the only way.

[Anonymous]

Thank you for your advice
Well ,the truth is, it has to be documeted . The best i can do so far (still working on it a bit) trying in AC shows in the render below.
It is made with profiler and trussmaker (only have demo version of ArchiForma ).
If i come up with something better, i will post it !
Thanks a lot!

[Karl Ottenstein]

teOS wrote:
Thank you for your advice
Well ,the truth is, it has to be documeted . The best i can do so far (still working on it a bit) trying in AC shows in the render below.
It is made with profiler and trussmaker (only have demo version of ArchiForma ).
If i come up with something better, i will post it !
Thanks a lot!

Very nicely start! Yes, if it has to be documented, then full modeling is the only way as Djordje and you say.

(If you have to do renderings, and your building has very many of these braces, I still might suggest making a low polygon-count version using my technique and putting the modeled braces in a layer visible where they are required, and the low polygon ones in a layer visible otherwise... otherwise things could get quite slow...)

Karl