to retopo or no topo, that is my question ?

Can any one tell me if i have to retopo the vertices in a sculpt done entirely in blender to proceed in painting it and using it in conjunction with other art created in blender. i know i have to with sculptris to blender imports if the face count is high, but my question is suppose i do all the sculpting in blender and still have a high face count, do i need to retopo ? thanks for any help and guidance.

I would retopo and then bake the details to a normal map with a uv mapped image on the lower resolution retopo mesh.

The main problem with sculpts is the polycount that can get quite high when you want to sculpt some finer details.
And in Blender high poly models are very difficult to use in Texture Paint mode because unless you have a powerfull computer , it will be painfully slow.

So even with a sculpt made in Blender, retopo is always a good idea, as Craig Jones said, you can use the Blender bake function to create a normal map that will allow you to get the details of the high poly sculpt on your lower poly retopo as described in this short written but good tutorial :

Using a retopo, that will be then lower poly will allow you to use the Texture Painting mode in a much more enjoyable way, as you’ll get very smooth experience.
A tutorial (video this one) that could proves usefull to you too :

On the other hand… if the sculpt is multires-based, lower levels can be used for the painting.

I’d say this depends a lot on what you have, and what you want to use it for.
In some cases retopo is absolutely necessary, in some cases a waste of time. Unless you count goodlooking showreel breakdowns.

True, i wasn’t thinking of the multires modifier, texture painting has a very good use of it !

Thankyou .Craig, Sanctuary & Encen. i will check these tutorials & follow your advice. i guess i was hoping there was an easy way out. thanks again. bs.

The multires modifier is actually the easy way out.

An example of how it work.
You have your base model, ready for sculpting.
You add then a multires modifier to it
http://i.imgur.com/DkphN.jpg

Not much to do at multires level 0 , so click on the subdivide button to go to the level 1 of the multires, then you can start to roughly sculpt (not yet enough faces for real detailling)
http://i.imgur.com/7IF1s.jpg

Once you can’t really do more, click on the subdivide button to go to the level 2, and sculpt more
http://i.imgur.com/6SPyj.jpg

When you can’t sculpt more, add another subdivide level to the multires and sculpt finer details
http://i.imgur.com/d4HIT.jpg

And again, repeat
http://i.imgur.com/fwl2o.jpg

Blender sculpt mode work very differently than sculptris, more than just the technical aspect, Blender scullpt mode has more to do with sculpting “progressively” adding a subdivision level when you need more details, while Sculptris gives you complete freedom from the start to the end.

When you will want to paint, you edit the multires modifier settings to go back to a lower multires level, unwrap in edit mode, and you can paint.

But the main problem with the Blender method in comparison to Sculptris is that when you subdivide, it will subdivide the whole model, and so may add a very lot of faces when you don’t really need, so you’ll see that in the end you’re going to have to carefully check the face count, as at some point, unless you have a good computer+graphic card, you’re going to have some performance problems.

Some hints on how to improve performance :

For the model, disable “Double sided” if it is enabled
http://i.imgur.com/TdrBe.jpg

Make sure that your model is smooth shaded, not flat shaded (in my screenshot it’s flat shaded, but only to show you the difference in face count)
http://i.imgur.com/W9vLr.jpg

If you have a good graphic card, you can enable VBO (in File -> User Preference -> System, you should see a “VBO” button, disabled by default) it apparently make a huge difference, but if your graphic card is not good enough, enabling VBO will do nothing and may crash Blender in a few cases.

Start with a model base that is at least 1000 or more faces, do not start with adding multires modifier to the default cube by example, it will be rather bad in higher multires level.

In the Sculpt mode, enable “Fast Navigate”, it allow Blender to display a lower poly version of the high poly sculpt you’re working on when you rotate around it (allowing then to rotate quickly), i wish the devs would have included zooming in/out in the "Fast Navigate though.
http://i.imgur.com/sLAWV.jpg

At rather high polycount, it’s good to zoom in the zone you’re sculpting, it will help the brushes to stay smooth.

If you use a recent build of the Blender svn (like one from the buildbot), there’s now the partial visibility feature included in sculpt mode, that allow to hide part of your sculpt.
And it works then like in Sculptris : what you hide does not impact performance anymore, so you are able to sculpt on polycount levels that may have crippled your Blender experience before.

“stable” Blender 2.63 that should be released in a week or two will have this function.

when you sculpt at higher sub level does it means that the whole mesh has been subdivided or is it local ?

thanks

In Blender it’s the whole mesh that is subdivided. That’s why the Unlimited Clay was an interesting project, as it allowed only local subdivision, like Sculptris does.

so has soon has you increase multire level to add more smaller details it will automatically increase verts count all over !
even if you come back to a lower level afterward!

then i hope we get this UC has soon has possible
but ther is the dynamic xyz something but not certain what the differences is anymore !

thanks

I will give the multires mod a try. thanks. i have 1 last question, if i sculpt an object in sculptris & use the reduce selected option to lower the triangle face count drasticley , can i import into blender w/o retoppo or is it the shape of the vertices ( triangles) that also create the need for retoppo ? thanks again, you all are so much help…bs.

In the end it all depends on how Blender will behave with the model.
If Blender Texture Painting mode is smooth with it, no need of retopo.

But one thing, before going to Texture Paint mode, you will need to :
-unwrap the model
-assign a texture to it.

Or the Texture Paint mode will not work.

Thanks again brother, i bookmarked and downloaded the tutorials and will take some time to study them. thanks for all your help Sanctuary & thankyou to all ! …bs.

One other thing worth mentioning. A lot depends on the extent of your scuplting and how closely it follows the base mesh (if any). For example, I was working on a spider and had a pretty good base mesh. I used scuplting for some fine details, but no really significant changes that would require retopo. I baked everything and kept the base mesh and things were just fine. No need for retopo.

There are some really good tutorials on blendercookie.com about scuplting and retopo. Here are a few good ones that I have used:
http://cgcookie.com/blender/2011/05/23/texturing-and-rendering-an-elf-head-in-blender-part-01/
http://cgcookie.com/blender/2010/09/28/house_elf/
http://cgcookie.com/blender/2011/07/08/creating-a-damaged-pillar-part-01/

-unwrap the model
-assign a texture to it.

Or the Texture Paint mode will not work.

is this same thing then the sculpt texture painting ?

cause i check the bolts file using alpha and normal map and i cannot see an unwrap for the plane !

thanks

I’m not sure what you mean by Sculpt texture painting and which bolt are your refering to ?

What i mean is that for the Texture Painting mode to work, your model must first be unwrapped, and in the UV/Image Editor you must have created a new image (or loaded a texture) for it to be assigned to that model.

With a texture being assigned, Blender does not know where to paint, and so the Texture Painting mode will stay stuck.

Now it is possible to paint on a model that has no UV and no texture assigned, in the Vertex Paint mode, but to obtain any good result, it is important to have a high density on your model, giving then possible performance problems on larger models.

sorry i kind of fell off of this one. im still trying to learn to unrap things. i need to see more tutes on this and on tex paint. i try to use tex paint & it wont respond & freezes up & crashes even trying to paint a cube. i try to watch some tutes and you can barely hear them, even on full vol. thanks for your help , i will press on forward. bs.

The main reason of why Texture Paint mode just do not respond to your brush stroke is that you have the model :

  • not unwrapped
  • unwrapped but without a texture being assigned to it.

If you have not yet learned how to unwrap, you can use the “Smart Unwrap” function, it works a bit like the automatic unwrap that Sculptris does, it create half of the time horrible uv map, but just for painting on the model they work well enough.

An example with the cube.

  • Select the cube , go to Edit Mode
    In Edit Mode split the screen in 2 , the left one you’ll keep it being the 3D view, but the right one you’ll change it to "UV/Image Editor

  • In the UV/Image Editor click on Image -> New Image
    There you can define which color, size that default texture will be, you can have it being a checkerboard if you want (by enabling the “UV Test Grid”.
    Once you have defined your image it will appear in the UV/Image Editor
    http://i.imgur.com/Z2EHY.jpg

-Back to the 3D view, in Edit Mode, select all the cube if it’s not yet selected and press U
In the popup menu, select Smart UV Project
At “UV Island Margin” , instead of 0 set it to 0.10 , it will prevent some problems later when painted could get on a wrong island.

  • You’ll see the UV Map in the UV/Image Editor appear
    http://i.imgur.com/nx1BA.jpg

You now have the cube unwrapped and a texture assigned to it.
In the 3D View, instead of Edit Mode, change it to Texture Painting mode and test it.
http://i.imgur.com/Jilpm.jpg

Remember to save the texture when you want to stop or you’re finished with it, in the UV/Image Editor, click on Image -> Save As Image and save it where you want.

you could also load an image for some texture like dust or clouds ect
then you can paint this on your object also
then change the texture to something else and paint abnothe texture again somewhere else !

i wish we could paint some bump map also that woudl be cool !

salutations

you can, thanks to the Layer Manager addon (that is in User Preferences -> Addons -> Paint) :

But you need GLSL to be fully supported by your card to see the effect in real time.
If your card can’t do, you can see the effect only in rendering.