Hey guys, I decided to give the High to Low poly modelling workflow a try with this model, a Walther PPK. I've made my high and low models but I'm having real difficulties getting my RTT to work properly. I've also explored into using Xnormal as well, as an alternative to 3Ds Max's RTT but I'm finding sometimes I get a good result with some blatant errors and other times it's just no use at all.

I could really use some help with this, because the project has been going really smoothly until now and I'm going nuts trying to get it to work.

Here's the models:



The UV template I'm using:



Here's the render to texture settings I've been using in Max:



Basically, the problem I'm having in Max is the speed at which it renders. It takes far longer than I'd expect a computer of my spec to take and it frequently lags my computer as well while rendering. The end result isn't what I expect either. For example:



In Xnormal, it's a bit different. I have no experience using it but I think I've got the idea. These are the results I'm getting though:



Which is closer to what I want, but I can't figure out why the trigger area is messed up. and when I try to render in Xnormal with different .obj this is what I tend to get:



So, as you can see, lot of problems and a lot of frustration. I'm sure it's my inexperience with this pipeline that's the main problem but any help anyone can give me would be fantastic. I realise it's a lot to look at but if there's anything I've missed or that you need a screenshot of, just say and I'll do my best to provide. I'm loving the project but this wall is driving me insane.

Please oh please dont tell me that your whole gun is one smoothing group!

there is a reason that smoothing groups excist. you are supposed to SPLIT your mesh in to manageable smoothing "islands"

What i usually do is first I UV the weapon, splitting the UV's at <90 degree angles, while also making sure I dont get too much stretching or warping in my UV.

After that, I use Textool's UV from Smoothing group feature, which automatically applies seperate smoothing groups to each UV island.

If you do that, I guarantee you wont go wrong.

Originally Posted by Olli.

Please oh please dont tell me that your whole gun is one smoothing group!

there is a reason that smoothing groups excist. you are supposed to SPLIT your mesh in to manageable smoothing "islands"

What i usually do is first I UV the weapon, splitting the UV's at <90 degree angles, while also making sure I dont get too much stretching or warping in my UV.

After that, I use Textool's UV from Smoothing group feature, which automatically applies seperate smoothing groups to each UV island.

If you do that, I guarantee you wont go wrong.

Ah okay, sorry, It is. I'm getting very confused about baking actually as I have people telling me the low should be all one smoothing group and others saying it shouldn't. Is it bad practice or is it a personal opinion thing?

I'll get to trying out that suggestion though!

It's a matter of where you want to render it really or what engine you're going to use it show your stuff, it's basically an issue of Tangents (the math which tells how the Normal Map will be processed and shown) so you will avoid seeing any nasty seams.

A quick idea on why people do the splitting thing.

As for the splitting itself, anything that looks like it has a harsh angle, 75-90 will need to be cut since harsh bends will create a gradient in your normal map. Basically, anything that is harsh like a box edge will need a nice cut to put it simply.

That's the most common way to do it, the other way is to put up some support loops (Google it to get an idea of what they look like) so that the Normal map has more vertices on which to interpolate the data and tighten it.

Next, you need to split your Smoothing from your UV's, I know that TurboTools (free script) allows you to do this, not sure if TexTools allows since last time I used it, it did the opposite and the site it down for me currently, so check this one out: http://www.matthewlichy.com/turboTools.html

After all that is done, you need to specify a cage, usually, it's something as simple as putting Cage modifier in Max on your Low-Poly, exporting it as a Mesh, adding a Push modifier and moving around the points, collapsing everything, and importing it back as a cage (please look up Cage and how to how export/import in Max and how to change the cage).

After ALL that, you can export your High Poly and Low Poly as an OBJ to Xnormal or use SBM, which is the best way to go about it, since it's respect stuff like the tangents, smoothing groups and UV's much more correctly then OBJ (which can sometimes break if Max doesn't like something).

Take a look at the PC wiki for more information about this.

Also, don't be afraid to put in a few extra UV cuts and here and there if it's required to make your life easier.