A question about modeling world surface

[sanbens1234]

If I want to model a terrain whose cross section is a specific height functions h(x) with respect to x-axis(see figure 1), is there any way to construct such terrain. It seems that hfield is not possible, because it is discrete and not smooth enough(see firgure 2). I wonder if it is possible to model the stl by myself, and then use CoACD library to turn it into convex objects( it seems that it may also not smooth enough?). Or is there any other efficient way? Thank you in advance!
figure1

figure2

[yuvaltassa]

I don't understand why you are getting these "staircase" jumps. It should be smooth.

Here, I made you an example:

hfield.mp4

<mujoco>
  <asset>
    <hfield name="example" size="0.9 1.1 1 .1" nrow="50" ncol="20" elevation="
      0.303  0.348  0.384  0.411  0.424  0.421  0.399  0.353  0.278  0.166  0.     0.166  0.278  0.353  0.399  0.421  0.424  0.411  0.384  0.348
      0.301  0.346  0.382  0.409  0.423  0.422  0.402  0.362  0.299  0.218  0.166  0.218  0.299  0.362  0.402  0.422  0.423  0.409  0.382  0.346
      0.293  0.339  0.376  0.404  0.421  0.424  0.412  0.384  0.342  0.299  0.278  0.299  0.342  0.384  0.412  0.424  0.421  0.404  0.376  0.339
      0.281  0.327  0.366  0.396  0.416  0.424  0.421  0.406  0.384  0.362  0.353  0.362  0.384  0.406  0.421  0.424  0.416  0.396  0.366  0.327
      0.265  0.31   0.35   0.382  0.406  0.42   0.425  0.421  0.412  0.402  0.399  0.402  0.412  0.421  0.425  0.42   0.406  0.382  0.35   0.31
      0.243  0.289  0.329  0.363  0.39   0.409  0.42   0.424  0.424  0.422  0.421  0.422  0.424  0.424  0.42   0.409  0.39   0.363  0.329  0.289
      0.217  0.262  0.303  0.339  0.368  0.39   0.406  0.416  0.421  0.423  0.424  0.423  0.421  0.416  0.406  0.39   0.368  0.339  0.303  0.262
      0.187  0.231  0.272  0.308  0.339  0.363  0.382  0.396  0.404  0.409  0.411  0.409  0.404  0.396  0.382  0.363  0.339  0.308  0.272  0.231
      0.154  0.196  0.236  0.272  0.303  0.329  0.35   0.366  0.376  0.382  0.384  0.382  0.376  0.366  0.35   0.329  0.303  0.272  0.236  0.196
      0.118  0.158  0.196  0.231  0.262  0.289  0.31   0.327  0.339  0.346  0.348  0.346  0.339  0.327  0.31   0.289  0.262  0.231  0.196  0.158
      0.08   0.118  0.154  0.187  0.217  0.243  0.265  0.281  0.293  0.301  0.303  0.301  0.293  0.281  0.265  0.243  0.217  0.187  0.154  0.118
      0.042  0.077  0.11   0.141  0.169  0.194  0.215  0.231  0.243  0.25   0.253  0.25   0.243  0.231  0.215  0.194  0.169  0.141  0.11   0.077
      0.004  0.035  0.065  0.094  0.12   0.143  0.163  0.178  0.19   0.196  0.199  0.196  0.19   0.178  0.163  0.143  0.12   0.094  0.065  0.035
      -0.032 -0.005  0.022  0.047  0.071  0.092  0.11   0.124  0.135  0.141  0.143  0.141  0.135  0.124  0.11   0.092  0.071  0.047  0.022 -0.005
      -0.066 -0.043 -0.02   0.003  0.024  0.042  0.058  0.071  0.08   0.086  0.088  0.086  0.08   0.071  0.058  0.042  0.024  0.003 -0.02  -0.043
      -0.097 -0.078 -0.058 -0.039 -0.021 -0.005  0.009  0.02   0.029  0.034  0.035  0.034  0.029  0.02   0.009 -0.005 -0.021 -0.039 -0.058 -0.078
      -0.124 -0.108 -0.092 -0.077 -0.062 -0.048 -0.036 -0.027 -0.02  -0.015 -0.014 -0.015 -0.02  -0.027 -0.036 -0.048 -0.062 -0.077 -0.092 -0.108
      -0.146 -0.134 -0.121 -0.109 -0.097 -0.086 -0.077 -0.069 -0.063 -0.059 -0.058 -0.059 -0.063 -0.069 -0.077 -0.086 -0.097 -0.109 -0.121 -0.134
      -0.162 -0.154 -0.145 -0.136 -0.127 -0.118 -0.111 -0.105 -0.1   -0.097 -0.096 -0.097 -0.1   -0.105 -0.111 -0.118 -0.127 -0.136 -0.145 -0.154
      -0.173 -0.168 -0.162 -0.156 -0.15  -0.144 -0.138 -0.134 -0.13  -0.128 -0.127 -0.128 -0.13  -0.134 -0.138 -0.144 -0.15  -0.156 -0.162 -0.168
      -0.177 -0.176 -0.173 -0.17  -0.166 -0.162 -0.159 -0.156 -0.153 -0.152 -0.151 -0.152 -0.153 -0.156 -0.159 -0.162 -0.166 -0.17  -0.173 -0.176
      -0.177 -0.178 -0.178 -0.177 -0.175 -0.174 -0.172 -0.17  -0.169 -0.168 -0.168 -0.168 -0.169 -0.17  -0.172 -0.174 -0.175 -0.177 -0.178 -0.178
      -0.17  -0.174 -0.176 -0.177 -0.178 -0.178 -0.177 -0.177 -0.177 -0.176 -0.176 -0.176 -0.177 -0.177 -0.177 -0.178 -0.178 -0.177 -0.176 -0.174
      -0.159 -0.164 -0.168 -0.171 -0.174 -0.175 -0.176 -0.177 -0.177 -0.177 -0.177 -0.177 -0.177 -0.177 -0.176 -0.175 -0.174 -0.171 -0.168 -0.164
      -0.142 -0.149 -0.155 -0.16  -0.163 -0.166 -0.168 -0.17  -0.171 -0.172 -0.172 -0.172 -0.171 -0.17  -0.168 -0.166 -0.163 -0.16  -0.155 -0.149
      -0.122 -0.131 -0.137 -0.143 -0.148 -0.152 -0.155 -0.157 -0.159 -0.16  -0.16  -0.16  -0.159 -0.157 -0.155 -0.152 -0.148 -0.143 -0.137 -0.131
      -0.099 -0.108 -0.116 -0.122 -0.128 -0.133 -0.136 -0.139 -0.141 -0.142 -0.142 -0.142 -0.141 -0.139 -0.136 -0.133 -0.128 -0.122 -0.116 -0.108
      -0.074 -0.083 -0.091 -0.098 -0.105 -0.11  -0.114 -0.117 -0.119 -0.12  -0.121 -0.12  -0.119 -0.117 -0.114 -0.11  -0.105 -0.098 -0.091 -0.083
      -0.048 -0.057 -0.065 -0.072 -0.078 -0.084 -0.088 -0.091 -0.094 -0.095 -0.096 -0.095 -0.094 -0.091 -0.088 -0.084 -0.078 -0.072 -0.065 -0.057
      -0.021 -0.03  -0.038 -0.045 -0.051 -0.056 -0.061 -0.064 -0.066 -0.068 -0.068 -0.068 -0.066 -0.064 -0.061 -0.056 -0.051 -0.045 -0.038 -0.03
      0.006 -0.003 -0.01  -0.017 -0.023 -0.028 -0.032 -0.036 -0.038 -0.039 -0.04  -0.039 -0.038 -0.036 -0.032 -0.028 -0.023 -0.017 -0.01  -0.003
      0.031  0.023  0.016  0.01   0.004 -0.    -0.004 -0.007 -0.01  -0.011 -0.012 -0.011 -0.01  -0.007 -0.004 -0.     0.004  0.01   0.016  0.023
      0.053  0.047  0.041  0.035  0.03   0.026  0.022  0.019  0.017  0.016  0.016  0.016  0.017  0.019  0.022  0.026  0.03   0.035  0.041  0.047
      0.073  0.068  0.062  0.058  0.053  0.05   0.047  0.044  0.042  0.041  0.041  0.041  0.042  0.044  0.047  0.05   0.053  0.058  0.062  0.068
      0.089  0.085  0.081  0.077  0.074  0.071  0.068  0.066  0.065  0.064  0.063  0.064  0.065  0.066  0.068  0.071  0.074  0.077  0.081  0.085
      0.101  0.098  0.096  0.093  0.09   0.088  0.086  0.084  0.083  0.082  0.082  0.082  0.083  0.084  0.086  0.088  0.09   0.093  0.096  0.098
      0.11   0.108  0.106  0.104  0.102  0.101  0.099  0.098  0.097  0.097  0.097  0.097  0.097  0.098  0.099  0.101  0.102  0.104  0.106  0.108
      0.113  0.113  0.112  0.111  0.11   0.109  0.109  0.108  0.107  0.107  0.107  0.107  0.107  0.108  0.109  0.109  0.11   0.111  0.112  0.113
      0.113  0.113  0.114  0.114  0.114  0.113  0.113  0.113  0.113  0.113  0.113  0.113  0.113  0.113  0.113  0.113  0.114  0.114  0.114  0.113
      0.108  0.11   0.111  0.112  0.112  0.113  0.113  0.113  0.113  0.113  0.113  0.113  0.113  0.113  0.113  0.113  0.112  0.112  0.111  0.11
      0.1    0.102  0.104  0.106  0.107  0.108  0.109  0.109  0.11   0.11   0.11   0.11   0.11   0.109  0.109  0.108  0.107  0.106  0.104  0.102
      0.088  0.091  0.094  0.096  0.098  0.099  0.1    0.101  0.102  0.102  0.102  0.102  0.102  0.101  0.1    0.099  0.098  0.096  0.094  0.091
      0.074  0.077  0.08   0.083  0.085  0.087  0.088  0.09   0.09   0.091  0.091  0.091  0.09   0.09   0.088  0.087  0.085  0.083  0.08   0.077
      0.057  0.061  0.064  0.067  0.07   0.072  0.074  0.075  0.076  0.076  0.076  0.076  0.076  0.075  0.074  0.072  0.07   0.067  0.064  0.061
      0.039  0.043  0.046  0.05   0.052  0.055  0.056  0.058  0.059  0.059  0.06   0.059  0.059  0.058  0.056  0.055  0.052  0.05   0.046  0.043
      0.02   0.024  0.028  0.031  0.034  0.036  0.038  0.039  0.04   0.041  0.041  0.041  0.04   0.039  0.038  0.036  0.034  0.031  0.028  0.024
      0.001  0.005  0.008  0.012  0.014  0.017  0.018  0.02   0.021  0.022  0.022  0.022  0.021  0.02   0.018  0.017  0.014  0.012  0.008  0.005
      -0.017 -0.014 -0.01  -0.008 -0.005 -0.003 -0.001  0.001  0.002  0.002  0.002  0.002  0.002  0.001 -0.001 -0.003 -0.005 -0.008 -0.01  -0.014
      -0.034 -0.031 -0.028 -0.026 -0.023 -0.021 -0.019 -0.018 -0.017 -0.017 -0.016 -0.017 -0.017 -0.018 -0.019 -0.021 -0.023 -0.026 -0.028 -0.031
      -0.05  -0.047 -0.044 -0.042 -0.04  -0.038 -0.037 -0.035 -0.035 -0.034 -0.034 -0.034 -0.035 -0.035 -0.037 -0.038 -0.04  -0.042 -0.044 -0.047"/>
  </asset>

  <worldbody>
    <light pos="0 0 2"/>
    <composite type="particle" count="4 4 4" spacing="0.1" offset="0 0 1">
      <geom size=".025" rgba=".8 .2 .1 1"/>
    </composite>
    <geom type="hfield" hfield="example"/>
  </worldbody>
</mujoco>

[yuvaltassa]

Also, please use issues rather than discussions.