I haven’t mentioned anything yet, this time I will practice making a special photography aircraft and make some mechanical equipment that I like.
1. Production of low-module and high-module
The first step is to make the top view and divide it into parts.
Parts:
The general shape is complete. I almost vomited this cabin. The structure is quite complicated. I found that I didn’t understand the structure well enough. In order to separate some structures, I reworked it several times.
The next step is to make some adjustments to the overall structure, and then dig out a position reserved for the main gun in the lower part of the front half of the fuselage.
In addition, the structure of the front half of the fuselage needs some adjustments. The transition from the edge to the top/bottom is relatively smooth, with no small planes protruding from the edge.
Do some topology optimization. In some places, the topology is particularly messy due to convenience when making the appearance. Let’s reorganize it.
Cut the surface structure through K, and then expand + push and pull to create a engraved structure and make a high mold.
Due to my own inexperience, the structure of the front half of the fuselage was completely messed up (sad).
Comparing it with the low model (picture below), you can see that the level of detail in the cockpit was already a bit out of control when making the low model, so the corresponding parts were easier when making the high model.
2. Normal baking
Before normal baking, we have two prerequisites:
First, we need to UV expand the low model.
The second is to assign a material.
What I haven’t said yet, just deploy the smart UV and start it!
For some empty complete blocks in UV, we can move some widgets and scale them to fill in the corresponding positions to improve the texture utilization.
Next, create a material for the low-poly model, create a new blank texture, and rename it normal_bake.
In the rendering properties bar, adjust the rendering engine and select non-real-time rendering cycles. (Baking normals, is it too much to choose evee...)
It is also the rendering properties bar, pull down to adjust the baking parameters
. Note that the object we selected first is the selected object .
The objects we select later through ctrl are active objects .
Then click Bake.
2.1. Failed baking experience
As expected, he was immediately deflated without any courtesy. . .
Note that after the UV is expanded, the corresponding surface occupies too small an area in the map, and it is extremely easy for insufficient resolution to result in insufficient baking:
First, the sampling may be unclear and the normal information is full of noise.
Second, baking offset may occur. (This may be the result of my forced baking using a cover)
Please be sure to pay great attention to the complexity of low-model and the problem of UV area.
There is no other way. Now I face two paths:
- Re-expand the UV and increase the area.
- Redo the model to reduce complexity/number of faces.
It is obviously impossible to re-develop the UV as a whole model, or redo the structure. To make it easier, we can only make a separate material for each part / attach a set of normal maps to each part.
Depending on the situation, some relatively small parts may be merged with line maps (such as wings and several cannons that are not high-modeled, so no additional normal maps will be baked). This way the workload is slightly smaller.
After re-expanding the UV and baking the normals, I still feel that the effect is not ideal.
2.2 Using mask mesh for normal baking
Instead of using a mask for baking, we copy a low model, scale it appropriately, and create a mask mesh that can cover the high model.
Choose to use a mask when baking normals.
The normals were baked successfully. (Don’t mention it, it’s not a skilled craftsmanship, only the outermost layer has engraved lines hahaha...)
In the same way, to complete the UV expansion of the cockpit, first intelligently expand it, and then manually adjust its layout.
Bake the normals again, and sure enough the quality is still not good.
After using the mask, after aligning the model, I found that my hand had not adjusted the size when making the high model, which made it difficult for the mask mesh to cover the high model. I could only use the high model to make a new low model. come out.
2.2.1 Frequently asked questions about normal baking
Surface information is missing during normal baking
One is to select the newly created normal image map in the rendering window.
The other is to ensure that the positions of the high-poly and low-poly models coincide .
Otherwise, it is easy to have a series of problems such as incomplete baking and leaking noodles.
When baking normals, the positions do not overlap. The only structure that was baked out was that I missed the line selection and accidentally made a convex structure. I was so angry.
Select the new normal map.
Structural details lost during normal baking
The red part is the convex structure, and the orange part is the concave structure.
In addition, for engraved structures with vertical normal lines, the baking effect is often poor. If the orientation of the recessed surface is adjusted so that the edge surface is uniformly inclined, the baking effect will be greatly improved.
3. Bone binding
Because it is necessary to control the wings and main turret, it is necessary to bone bind the gun body and wings.
Unlike the binding of the human model, the hard surface model moves as a whole, so it only needs to be attached with an empty fixed point group.
For human model binding, you can refer to my previous notes.
In object mode, select the corresponding component, activate the skeleton, and attach an empty vertex group.
In edit mode, select all vertices and assign them to the vertex group of the corresponding bone.
Because the predecessor cannot be opened infinitely, it is necessary to add limits to the corresponding bones.
Switch to attitude mode for testing.
If the mirror effect of the posture response is wrong, you should confirm the positional relationship between the skeleton's modifier and the mirror modifier.
In the same way, create the bone binding of the wing and add rotation restrictions.
Like in the play, when the variable wings are adjusted, the mechanism of the small wings retracting at the same time is difficult to achieve in pure binding, so we chose to make this setting during animation production.
4. Use substance painter to draw the paint
Before drawing, we need to ensure that all parts have been UV unfolded.
Generally speaking, UV expansion also needs to consider the issues of detail and UV utilization. In order to improve efficiency, we still directly use smart UV expansion here.
Blender exports the fbx model, sp creates a new project and imports the model.
Note that sp does not have settings to import models separately and needs to be imported directly when creating a new model.
The most basic interface control shortcut keys for sp:
alt + middle mouse button: pan the view
alt + left mouse button: rotate the view
mouse wheel: zoom
We need to bake the texture first and then draw it.
Choose 2k resolution for output, anti-aliasing 4x4.
The overall idea of drawing is also relatively simple. For large areas to keep the same color, we use a fill layer plus a black selection, and use a full hard stroke selection method to apply the background color. Of course, in the color mode, we first remove the attributes other than basecolor and only process the background color.
Taking the previous fuselage as an example, the basic color is completed by covering the entire base color.
Add some details. The metallic feeling here is not a solid color painting. Next, we click on some highlight colors to highlight the metal and transparency.
Next we need to control the metallicity of the entire front fuselage. By default, the entire front fuselage is shiny.
We need to make sure that only the parts with stronger metallicity have such a strong reflection, but what we need to control here is not the metallicity, but the roughness.
Again, we use the paint bucket (cover) layer, give it a white mask (because the black parts are mainly roughness 0 parts, and white represents higher values), and then manually control the smooth parts.
The next step is to make the engraved lines. I ended up not using the high-poly baking method for the engraved lines here. For such small details, the baking effect is terrible. The drawing method of background color + metallicity is used here .
Since the pure black background color still maintains normal metallicity, it can reflect normally, making it different from the 0 metallicity part of the engraved line.
The basic drawing logic is as above, then the effect of completing the engraved line drawing is as follows
. In order to increase the amount of detail, we also used edge rust and dust surface to increase edge wear and surface dust, giving an effect similar to aging.
Another point is the logo problem. Since it is a mirror model with only one-sided UV, there will be problems with the logo mirror, so we can only solve this problem in blender.
5. Import into blender
Here we mainly import the textures into blender, using the classic pbr mode to export, using only the base color, metallicity and roughness maps.
5.1 Add correct symmetrical logo
We know that the symmetry logic of the text logo is different from the symmetry logic of the model. We need to maintain the reading order of the text. Next, we will add the logo.
We enabled the import image as plane plug-in to import the corresponding logo, but we found that since the logo is independent of the material, the amount of information appears to be quite different, and the integration with the nose painting is insufficient and quite abrupt.
We directly use the predecessor textures to multiply and fuse the output texture materials. However, due to the inconsistent positions of the UVs, we can only alleviate the abruptness problem to a certain extent. The best way is to separate the positions corresponding to the logo and make a separate texture.
After completing the basic processing, enable the mirror modifier, and enable uv mirroring while axial mirroring.
A version of the Dyna logo was also made.
Similarly, we need to bind the logo to the corresponding bones to ensure that it can follow the movement.
5.2 Complete action production
Next apply all mirroring and rebind the bones. I haven’t done bone binding for a long time, and I suddenly forgot that Blender can only do x-axis symmetry for bone symmetry, which is a waste of time. . .
Reassign the fixed-point group and complete the binding. For a symmetrical bone, the direction of its rotation constraint axis should be opposite.
How to toss the key frames, refer to the past notes
[Blender Action Trainee] Bone Binding Learning from Scratch vol.3
mainly made simple actions, such as opening/closing the front fuselage gun bay, folding/expanding the wings .
