So, let's come to the point!
First of all, I personally had made bad experiences with using the cage with projection rendering. So I developed my way to bypass these problems I faced. If somebody feels he knows a better way, let me know.
Preparation
First I make a copy of the low poly body, which will be the actual object to be exported and directly hide it. Remember, in part 3 I asked you to do a normal render to texture as described in my tutorial in the Trainz-Wiki. So by now we have the body fully mapped (see section C in picture 01) and we (hopefully!) have an uvw file, where the mapping is stored.
For we need only the front of the safe, I detached it from the rest o the mesh. Visible should be now the detached front only and the high poly front, the VrayPlane and the VrayLight. All the rest should be hidden by now. The high poly front should be in the x- and z-axis exact at the same position as the low poly front, but it shall not overlap in the y-axis. If it is some millimeters away in the y-axis it doesnt matter, but not too far to avoid distortions.
Now we select the low poly front and hit the key 0 for render to texture. The further numbering refers to picture 01.
1. Make sure you choose the right path, where your textures shall be stored.
2. Make sure the right object is selected for the render process.
3. Projection Mapping has to be ticked (enabled on)!
4. By clicking on Pick... we come to a dialog where we can choose the object/s which shall be projected onto our front. Select the high poly front and close the dialog.
5. The Options.
5.1. As metioned before, switch Use Cage off.
5.2. Switch Ray miss check off.
6. This point is very important! Set Use Existing Channel on, because we do want to render exactly to the position into the mapping which already exists. The front has already a mapping, there the rendered texture shall go.
7. Now click on Add... and choose the desired map types. For our purposes we need (Vray)CompleteMap and (Vray)NormalsMap. Vray is in parentheses because for other renderer you should use the map without the Vray prefix. Feel free to use other map types too, some people are magicians with texture processing…
8.Choose a desired resolution for all maps. I choose here 2048x2048, because this is only an example. Normally I choose much higher values, especially if there are tiny details and later I reduce the resolution within a image processing program like Gimp or Photoshop. This I do because the quality of a reduced image is much better than one which is rendered in low resolution.
9.For we want to process the material ourselves activate Render to Files Only. This makes sure Max do not create a new sub material but stores the result in files only.
10. Before you click on Render, make sure you use the highest possible settings for the quality within the Render Setup window. But remember rendering in high quality needs a lot of time! So it might be a good idea to set the resolution (see 8.) first to 256x256 and check the result in an image program first, to see if it is somehow close to what you expected.
Post Production
If you have the final textures you will see, that the front part (Section A in picture 01) is in the exact position where the front is in the texture produced in part 3 of this tutorial (Section C in picture 01). All other parts are plain black. The normals map (Section B in picture 01) you can use directly without changes. We do have to trick around a little to get the front part only into our main texture file. Simply copy will not do the job, because the pure black part will cover all the rest. I use within Photoshop the Magic Wand Tool with the lowest tolerance settings and click into the pure black part. Then I revert selection. Now only the front part is selected, which I copy and place it with Paste Special->Paste in Place into our main texture. Save it as tga and we are almost done.
Now within Max we hide everything except the copy of our safe body. We create a new standard material and name it safe.m.tbumptex. Our prepared main texture comes into the Diffuse slot, the normals map into the Bump slot. Please experiment with the intensity of the bump effect and watch the result in Trainz. Ranges from -999 up to 999 are possible. For this example I used 99.
Now we assign the new material to the copy, use the Unwrap UVW Modifier and load the uvw file (see Preparation). Done!
Export the object and see the result in picture 02.
I am aware, that this example is not really perfekt, simplified hinges and handles which are fine tuned also with projection rendering would look much better. This tutorial shall show only the basic principles. Trying out by yourself I am sure with this technology you are able to create marvelous detailed assets which still have a quite good performance…
Mick!
P.S.: The ready model is on its way to the DLS (MV_Render to Texture-Tutorial-Safe plain model,<kuid:206616:100012>)
Picture 01
Picture 02
First of all, I personally had made bad experiences with using the cage with projection rendering. So I developed my way to bypass these problems I faced. If somebody feels he knows a better way, let me know.
Preparation
First I make a copy of the low poly body, which will be the actual object to be exported and directly hide it. Remember, in part 3 I asked you to do a normal render to texture as described in my tutorial in the Trainz-Wiki. So by now we have the body fully mapped (see section C in picture 01) and we (hopefully!) have an uvw file, where the mapping is stored.
For we need only the front of the safe, I detached it from the rest o the mesh. Visible should be now the detached front only and the high poly front, the VrayPlane and the VrayLight. All the rest should be hidden by now. The high poly front should be in the x- and z-axis exact at the same position as the low poly front, but it shall not overlap in the y-axis. If it is some millimeters away in the y-axis it doesnt matter, but not too far to avoid distortions.
Now we select the low poly front and hit the key 0 for render to texture. The further numbering refers to picture 01.
1. Make sure you choose the right path, where your textures shall be stored.
2. Make sure the right object is selected for the render process.
3. Projection Mapping has to be ticked (enabled on)!
4. By clicking on Pick... we come to a dialog where we can choose the object/s which shall be projected onto our front. Select the high poly front and close the dialog.
5. The Options.
5.1. As metioned before, switch Use Cage off.
5.2. Switch Ray miss check off.
6. This point is very important! Set Use Existing Channel on, because we do want to render exactly to the position into the mapping which already exists. The front has already a mapping, there the rendered texture shall go.
7. Now click on Add... and choose the desired map types. For our purposes we need (Vray)CompleteMap and (Vray)NormalsMap. Vray is in parentheses because for other renderer you should use the map without the Vray prefix. Feel free to use other map types too, some people are magicians with texture processing…
8.Choose a desired resolution for all maps. I choose here 2048x2048, because this is only an example. Normally I choose much higher values, especially if there are tiny details and later I reduce the resolution within a image processing program like Gimp or Photoshop. This I do because the quality of a reduced image is much better than one which is rendered in low resolution.
9.For we want to process the material ourselves activate Render to Files Only. This makes sure Max do not create a new sub material but stores the result in files only.
10. Before you click on Render, make sure you use the highest possible settings for the quality within the Render Setup window. But remember rendering in high quality needs a lot of time! So it might be a good idea to set the resolution (see 8.) first to 256x256 and check the result in an image program first, to see if it is somehow close to what you expected.
Post Production
If you have the final textures you will see, that the front part (Section A in picture 01) is in the exact position where the front is in the texture produced in part 3 of this tutorial (Section C in picture 01). All other parts are plain black. The normals map (Section B in picture 01) you can use directly without changes. We do have to trick around a little to get the front part only into our main texture file. Simply copy will not do the job, because the pure black part will cover all the rest. I use within Photoshop the Magic Wand Tool with the lowest tolerance settings and click into the pure black part. Then I revert selection. Now only the front part is selected, which I copy and place it with Paste Special->Paste in Place into our main texture. Save it as tga and we are almost done.
Now within Max we hide everything except the copy of our safe body. We create a new standard material and name it safe.m.tbumptex. Our prepared main texture comes into the Diffuse slot, the normals map into the Bump slot. Please experiment with the intensity of the bump effect and watch the result in Trainz. Ranges from -999 up to 999 are possible. For this example I used 99.
Now we assign the new material to the copy, use the Unwrap UVW Modifier and load the uvw file (see Preparation). Done!
Export the object and see the result in picture 02.
I am aware, that this example is not really perfekt, simplified hinges and handles which are fine tuned also with projection rendering would look much better. This tutorial shall show only the basic principles. Trying out by yourself I am sure with this technology you are able to create marvelous detailed assets which still have a quite good performance…
Mick!
P.S.: The ready model is on its way to the DLS (MV_Render to Texture-Tutorial-Safe plain model,<kuid:206616:100012>)
Picture 01
Picture 02