General geometry - Model editing

General geometry - Pivot - Attaching models - Custom shaping - Texture mapping

General geometry

Let's try the work with the general geometry more practically by creating a chess model. To do this, we will need a couple of textures that you'll download here and we will first produce a pawn figure. On the 3D Models tab, select Elipsoid from the scroll and press Create. You can then rename the ellipsoid in the Name of the model field. Set the ellipsoid parameters as follows to create a paw head:

  • Radius A: 0,250
  • Radius B: 0,250
  • Height Seg: 8
  • Round Seg: 16
  • Cutting angle: 360

Now move the ellipsoid to the Z = 1.25 coordinate so that the pawn has the head at the correct height and its future base will just be on the XY plane. For further work, we need to convert the model to General geometry. This is done either by selecting Model - Convert to general geometry or by using the Ctrl + G key shortcut. As the name suggests, converting to general geometry cancels the parametric setting of the model shape, and on the contrary allows us to use the functions of editing its individual vertices, edges and faces of the model, according to our own desire.

Now we can start editing. First, make sure you still have our ellipsoid selected, click down arrow next to Freeze transformations and select Translation in the dialog that appears. This will return the model pivot to coordinates [0,0,0], so it will just stay on the chess board. On the left bar, you can also notice that by converting to general geometry, the fields for parametric setting of the ellipsoid disappeared. Instead, you can switch to the faces card on the same panel. In one of the viewports, select a side view with the edges displayed, and drag the mouse to mark faces of the first two rows from the bottom on the ball and delete them.

Now switch to the Edge editing tab and select the bottom ring of the edges left after deleting the faces of the sphere. Press the Extrude faces button to copy the selected edges and create faces between them and their originals. You do not see the new faces for now, because newly created edges are in place of the old ones. Sure you can see that the edges are still marked. However, only the new edges are marked and original edges have been unmarked by the program itself, so when you try to move the edges, for example, down the Z axis, say by -0.100, you will see that our newly created faces are emerging from the body. Press the Extrude faces button once again and move the edges again by -0.100 along to the Z axis.


Then, drag the mouse to select a horizontal ring of edges between these newly created two rows of faces. Surely you have also selected edges connected to them, so deselect the unnecessary edges by pressing Ctrl + Alt and again dragging mouse. You may have noticed that although the selected edges form a circle, their pivot is located slightly outside the Z axis. This is due to the fact that some body vertices are doubled. Usually, where each vertex needs to be textured with other UV coordinates or where the sharp edge of the body is. The Own pivot is always the arithmetic mean of the vertices of the currently selected parts of the model while the Synthetic pivot is a separate point that we can control and from the moment of the ellipsoids creation it is in the same place as Global pivot of the whole model - at the origin of the coordinates. We will want to stretch the selected edges more in width, so on the Edges editing tab switch to Use synthetic radiobutton in the Pivot section what anebales us to transform relative to the center of the selected circle. On the toolbar, select Scale and use the numeric fields at the bottom of the screen to stretch the selected edges in the X and Y axes by the same value. Note that current size is always considered as 100% if you want to scale up, enter a positive value of how many percent you want to enlarge. In the case of scaling down, enter the percentage as a negative value. We made to pawn an ornamental collar.

Tip: You can manually specify the coordinates of the synthetic pivot only at the Vertices adjustment tab, but its position is common for vertices, edges, and faces.

This part will be easy. Use the same features to shape the rest of the body on a pawn. Simply have selected the bottom circle of edges, use the Extrude faces button, and then scale more to width. It may be useful to perform the stretching in width using a synthetic pivot, but when moving it will be more convenient to switch back to the Use own radiobutton. When you are at Z = 0, you will surely want to make a pawns base. Make sure that you still have the lowest edge ring selected, use again faces extrusion, and then press the Merge button on the Edge editing tab. The edges collapse to one point and the newly extruded faces forms a circular base.

Maybe the faces of pawns entire body are flipped inside and you wonder why. This is because, when extruding out individual faces, they have a zero width, so you can not clearly determine which direction the faces have a normal vector oriented. Thus, in the direction of the positive values of the space axes, the faces have normals oriented outward and in the direction of the negative values, the faces have normals oriented inward. Now, it's enough to switch to the faces edit tab, drag the mouse to select badly reversed faces, and Flip to orient it back outside of the body.

Finally, we see that the pawn is shaped, but all its edges are smoothed. There are two ways to create sharp edges. The first option is to switch to Edge editing tab, select desired edges, and press Split. The second option is to switch to the faces edit tab, select the faces around which the sharp edge will be leading and press the Revert button. This leads to the flipping of the faces, but also to their physical separation from the surrounding faces, thus creating a sharp edge. By pressing the Flip button, we only flip the faces back outwards, but the sharp edge around them remains.

We will do the same thing as a pawn for the figure of the King, never mind that for example, his crown can feel more sophisticated. Extrude the crown from the king's head as an ordinary cylinder and, like the pawns base, create the top of the crown by extruding the faces out of the peripheral edges and merging them into one point. Then select each second vertex at the edge of the crown and move it down slightly to create the spikes on the crown. Now select top side of the crown, on the faces edit tab, use the buttons Revert and Flip again to separate the area from the rest of the model and move it up say for Z + 0.100. That's because we can now only select the edges of this part of the model. Switch to Edges editing tab to select all edges on the separate top of the crown, then press Split. Then move this part of the faces back down for Z - 0.100 to the King's crown.

Tip: As the second alternative to dividing edges is the Split option located on the vertices edit tab. Depending on the topology of the model faces, it may sometimes happen that when splitting the edges, there will be no separation of all theirs vertices. If shading does not match you desire, try to split vertices of the edges to achieve the correct effect.

Attaching models

We can make the figure of the bishop again easily from the already completed pawn. In the viewport or model list, select a pawn model. Duplicate it either by option Model - Duplicate or by Ctrl + D hotkey. Move a new copy little aside, and be sure to rename it right in the Name of the model field in the left panel. The bishop usually only has a more coned head than a pawn and we will arrange it here as follows. Select the bishop model, and switch to the vertices edit tab. Then select two opposing vertices in the center plane of the head of the figurine so that their pivot is in the center of the head. Downmost at the end of the vertices edit tab in the Pivot section, press the Synthetic = Own button to automatically move the synthetic pivot to the position of the selection pivot. Now select all the vertices at the top half of the bishop's head and switch in the Pivot section to Use synthetic radiobutton. You can see that the pivot cursor is still located in the center of the head and not in the middle of the selection. As a result, we can now stretch the bishop's head upwards by Scale to create a graceful conical shape.

Finally, for the more aesthetic look of the bishop we can add a decorative ball to the top of its cap. Just create a new ellipsoid that you place at the top of the bishop's head. To make the ball part of the bishop model itself, select the bishop model and go to the Element editing tab. Then, press the Attach model... button and select a ellipsoid from the list you see. The models are now connected in one.

One of the other options for making rotary shapes like chess pieces is to create a profile, which we along sequentional face extruding rotate around the synthetic pivot located in the models axis. For example, create Line from 2D models. The number of segments is not important, one is enough. After converting to general geometry pressing Ctrl + G switch to the vertices edit tab. Here, with the Extrude edges button, we can pull new edges with new vertices from the individual vertices, just like extruding faces when editing edges. So we can step by step by drawing the edge from the last vertex create outline of the future queens figure.

Tip: Also, when drawing the profile by extruding the edges, it is possible to attach the models on the element editing card to add other "wire" models - both parametric and general.

If we have the Queen's profile ready and the synthetic pivot we have placed in the models axis, we can select all the profile edges and create a queen figure with a simple procedure. So on the Edges editing tab switch Pivot radiobutton to Use synthetic. Then, extrude new faces from the selected edges, and turn the edges by Z axis by 22.5 degrees. Face extruding and rotating repeat until you fulfill 360 degrees. Attention: While rotating the extruded faces, the center vertices on the queen's head and base are copied several times, but simply merge them together with a Merge on the Vertices editing tab.

Tip: If you have extruded the edges from the vertices in different order, it may happen that the faces extruded from the edges will have a different orientation. In this case, you must select this faces area and orient it according to your needs by pressing the button Flip on Faces editing tab.

The last rotary figure is a rook that we can easily prepare from the cylinder. Make sure to have more than one segment on the base from the center to the edge. Thanks to this we can from border segments on the upper base by extruding the polygons (Faces editing tab - button Extrude polygon) and final faces adjustments create the battlements.

Custom shaping

Any irregular custom shapes as well as a knight figure require help of the further functions. We prepare a knight figure similar to the previous queen figure by drawing a horse's profile. Nevertheless, now everything depends only on our intention to shape the head into space. In addition to known face extrusion and so on, and the use of transformations, whether depending on own or synthetic pivot, we may need to create edges or faces individually between specific parts of the model.

Tip: The knight figure is symmetrical by its center plane, so we can only model one side of it. After that duplicate it Ctrl + D and mirror it to the other side. Then, you can select Attach model... in the original side model and join it with the new mirrored side together.

We create one edge by switching to the vertices editing tab. Select exactly two vertices to create the edge between and press Create edge. Attention: When more than two vertices are selected, the edge is not created because the program does not know which vertex pairs you want to link and which not. Similarly, you can make one faces with the Create face button, under the condition that you have exactly three vertices of the model selected. The face can also be created between the edges. Switch to Edges editing tab, select any two edges (exactly two) between which the face is to be created and then press the Create face button. The necessary condition is that these edges are already linked together by the same vertex. If edges do not have a common vertex, a new face will not be created.

Texture mapping

We will now give our figures material. Open the material setup window and click on the Diffuse button underneath the empty gray frames. The diffusion texture settings window opens, where you select the Open... button and choose the light wood texture in the dialog. Close the diffusion texture window again. In the field Spec. Exp. enter, for example, a value of 50 to make the figures shiny like glossy and polished wood. Without closing the materials window, you can now select the individual models in the scene and assign them new material by the Add button.

Most likely, the texture on the figures is distorted and chaotic, which is caused by the extrusion of edges and faces, when copying identical vertices with the same UV coordinates into the texture. Therefore, select the figure again and turn on the texture mapping. Either choose Model - Texture Mapping... or Ctrl + Shift + M. A window appears with the vertices layout in the UV space of the texture. Transforming vertices in this window is the same as transformations in 3D space viewports. Switch to the Parametric mapping tab, select the Planar radiobutton and enter 90 value in the Alpha field. This means that the wood material is projected on our model through a square canvas with a divergence of 90 degrees from the vertical Z axis - meaning horizontally. To apply these parameters, use the Proceed button. After returning to the UV Mapping tab, you can see that the vertices in the texture are similar in proportion to the model itself.

Tip: If you want to keep the exact proportions of the model in the texture when planar mapping, make new model - simple square - large enough to overlap your model and align these two behind themselves. When you edit the model itself on the Elements editing tab use the Attach model... button and add this square to the model. If you map the texture exactly perpendicular to the silhouette of this square, the model's proportions will be retained in UV texture mapping as well.

Finally, with the same functions described above, we create a playing board and lay out figures. The figures can be easily duplicated with the Ctrl + D shortcut, and for a better organization will serve that each has a unique name to distinguish the white set from the dark set.

You can try render the scene in the rendering setup dialog . We did not create any light source so the scene is lit only by the basic source at the point of the viewport camera and no shadows are cast. Therefore, we can place into the scene the light from the Cameras / Lights tab on the left panel at the top. Now render engine will react to its presence and renders the scene according to its parameters.

We made chess.

<< Return to topics

Copyright (c) 2013 - 2023

General terms and conditions

End user license agreement