Hi I am trying to combine these 2 meshses using dynamesh and then remesher, To make one mesh that I can add details to but I keep getting this result . Does anyone know how i can resolve this? Thanks in advance.
Instead of the subdivision levels you need to reduce the resolution slider in Dynamesh. Since you've got it set to 512 ATM, try 256.
The actual resolution is dependent on the model's size, shape, bounding box etc and is never really consistent (annoyingly).
Start low and work your way up to the highest resolution that works without holes/crashes, for something this simple you don't need the 9 million verts you currently have in that mesh.
Like Millenia said you need to reduce the resolution slider in Dynamesh. Dynamesh was never designed with really high poly count in mind. It was meant to be a useful tool to equalize the geometry during the sculpting process to easily create the base mesh. I would also recommend you to look at Dynamesh Master(Same thing but it gives you couple of more options like precisely setting the polygon count rather than using resolution slider.)
Unify it before dynameshing this will change set the size of the mesh to the preffered size to work with in zbrush. I believe unify is in te deformation tab. If that doesn't work go to geo modify topology check mesh and fix mesh.
Yes, setting your res that high -6 or 7 mill - is way over the top. Your mesh is just 3 very basic primitive shapes. As mentioned DM is scale dependant. Try it yourself on 2 copies of an object that are very different sizes. Notice the difference in mesh density
As @sunray says, working in ZB native scale is best for predictable results in general.
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The actual resolution is dependent on the model's size, shape, bounding box etc and is never really consistent (annoyingly).
Start low and work your way up to the highest resolution that works without holes/crashes, for something this simple you don't need the 9 million verts you currently have in that mesh.
As @sunray says, working in ZB native scale is best for predictable results in general.