Merging

#1 Joining them is just the first step: it makes them the same object. This will allow you to go into edit mode for both the cylinder and the semi sphere, where you can merge the vertices together (Alt+M) by the pair. You can then adjust the vertices separately for final adjustments.

In your case, I would merge the bottom vertices of the semi sphere to the closest vertices on the top of the submarine. But this can be quite a task as the sphere most likely has a lot more vertices than a cylinder does, especially the side faces of a cylinder. What you'll need is a fairly equal number of vertices on the each shape's surface area in which you need to join them. You can reduce the number of vertices on the bottom of the semi sphere by joining every other one with its neighbor, or you can increase the number of vertices on the cylinder by selecting two or more vertices and subdividing (W,1).

#2 Great response Jeffrey. Here also is an alternate method and is most likely the way I would attack the problem, especially if I was working on a low poly game model. Instead of merging together two primitive shapes, I would start with the frontmost edge loop of the cylinder and extrude it out a few times. I find it a little difficult in Blender to work with precise measurements (they're in there but not quite up-front) so I think it may be difficult to make the diameter of the semi-sphere match up exactly with diameter of the edge loop of the cylinder that you are trying to merge with. So, even if you remove doubles and alt-m until it is a contiguous surface, you still might find yourself with a little bump.

Here's a possible method for doing this on a low poly model.
1. Move the semi-sphere back in space. I will use this as a guideline for where to put the extruded loops.
2. Delete the vert that caps the front end of the cylinder. (this makes working with the first edge loop easier).
3. Select the edge loop.
4. View the sub from the ortho view that shows the silhouette of the sub (I will assume it is the front view for now).
5. Extrude along the x axis.
6. Scale the new loop so that it matches generally with the shape of the semicircle that is sitting behind.
7. Repeat a few more time. You probably only need 3 or 4 more loops for a game model.
8. After the final extrude, with your edge loop selected. hit alt-m to make a new cap.
9. Adjust visually (by selecting and scaling edge loops) to get the right curvature to your end. It may not match perfectly with the semisphere, but it will more likely not have any visible seams or bumps.

There, now there are two ways you can try. Let us know how it goes.

Scott

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The Low Poly Cooperative -- Open your mind to open content

#3 The sphere and the cylinder both have the same amount of vertices and I created them in the same spot and just shifted the sphere to the front. Nevertheless I'll try tonight, and let you know how it went :)
Thanks.

#4 Thanks, this was exactly the feature I was looking for.

Unfortunately my original problem wasn't solved by it :(
One can still see that it's not one shape in the rendered picture. Any ideas? I have the shape set to auto smooth and I did have that before on both shapes as well. Could it have to do with that?

#5 Which method did you use? Jeffrey's or mine?

Scott

#6 Jeffrey's method. I joined each point from the semisphere with the equivalent point of the cylinder. Then in the solid view, it did look right, just like one body, but in the rendered image it looked as if nothing had changed.

#7 Did you delete the vertex at the center of what used to be the endcap of the cylinder? Try that if you haven't.

Scott

#8 Okay, I did that, but no luck.

I think it might have to do with the amount of vertices on the side of the cylinder. The front and the back have the same amount as the sphere, but along the side, there are no additional vertices.

I made a similar model using bezier curves and a 360 degree spin. The same problem occured.

Is there a way to add more vertices to an existing cylinder?

Thanks.

#9 Think that way : for your submarine it's healthier to use game speciffic modeling techniques; that means that in a game world nobody cares if the submarine upper part is welded to the lower part. If looks welded it doesn't mean that is should be welded right there. Here is an example made in 3 mins for you:


the trick is how you texture the boat; it's all hollywood, friend, hollywood :)

#10 That's the "technique" I used before merging. I just fear that the lighting on the model will look strange eventually in the game, because I didn't merge them correctly.